wiki.openlighting.org - User contributions [en]

DMX512-A

2009-12-09T22:04:39Z

90.185.54.180: more clean-up, links to wikipedia

The last version of the standard is called [http://usitt.org/ USITT] DMX512-A and it is maintained by [http://esta.org ESTA] since 1998. In 2004 it was made an ANSI standard too, named "E1.11, USITT DMX512-A" or "ANSI E1.11-2004". In 2008 it was revised [http://www.esta.org/tsp/news/newsdetails.php?newsID=291] .

IF you are looking for info about connecting DMX equipment and setting addresses, look at this [http://www.youtube.com/view_play_list?p=F66259177229499F&search_query=martin+training+dvd+dmx video tutorial from Martin].
So far, the rest of this article is about technicalities.

DMX is characterized by its '''simplicity''' in how data are transferred from a controller to receiving equipment.

== Electrical ==
DMX is based on the balanced serial connection standard [http://en.wikipedia.org/wiki/EIA-485 EIA-485-A] (a.k.a RS485).
Only 5-pin [http://en.wikipedia.org/wiki/XLR_connector XLR] meets the standard (and products may meet the requirement by supplying adapters).
Since the revision in 1998 the cables itself are not specified in DMX512-A (so it can be specified in separate standards?)
In general the cable must fulfill the [http://en.wikipedia.org/wiki/EIA-485 EIA-485] requirements of 120 Ohms (around 250 kHz) shielded twisted pair. One transmitter must be connected to maximum 32 receivers.
* Termination resistor tolerance is 120 Ohm +5 % / -10 % (108 – 126 Ohm).
* Each receiver must not load the differential line with more than 125 pF.

=== Use of category 5 UTP or STP ===
Other cable types have been examined to determine how well they are for DMX usage (as loose cables or in fixed building installations). The last report more or less concludes that for fixed installations, unshielded twisted pair in [http://en.wikipedia.org/wiki/Category_5_cable CAT 5] is good enough, even when it is mixed with 120 Ohm cable meant for EIA-485. The pulses from reflections and general degradation is not significant and harmless. See the three parts at http://www.esta.org/tsp/working_groups/CP/DMXoverCat5.htm .

See also this point in USITT's DMX faq:
http://www.usitt.org/DMX512FAQ.aspx#a9
(old link is [http://www.usitt.org/standards/DMX512_FAQ.html#FAQ_08]).

The cabling for DMX512-A should be described in the document called "BSR E1.27-1 -- Portable Control Cables for Use with USITT DMX512/1990 and E1.11 [DMX512-A]"

The [http://en.wikipedia.org/wiki/8P8C 8-position modular connector] is allowed in the DMX512-A as an alternate connector if there is not space enough for XLR5 or for fixed installations in "controlled access areas".
Pin-out:
{|border=1
||Pin || Function
|-
|1 || data 1+
|-
|2 || data 1-
|-
|3 || data 2+
|-
|6 || data 2-
|-
|4 || Not assigned
|-
|5 || Not assigned
|-
|7 || Data link common for data 1
|-
|8 || Data link common for data 1
|}

Both common wires are mandatory, and must have same potential in equipment sockets.

=== Voltages and power dissipation===

The power dissipation in the 120 Ohm terminating resistors depends on the differential voltage between the two data wires.
If the transmitter only makes a 5 V differential voltage (which is common), the power dissipation is P= U*U/R= 5*5/120 = 208 mW.

According to [http://focus.ti.com/lit/an/slla070c/slla070c.pdf] and the DMX512-A standard, the maximum absolute differential voltage allowed by the EIA485 standard is 6 V.
This gives the maximum power dissipation is P= U*U/R= 6*6/120 = 300 mW. So it is best to use 1/2 W resistors, to keep them cool enough not to damage itself or weakening the solderings.

Transceiver chips made for 5 V (they seem to be widely used):
Linear Technology LTC485: [http://www.linear.com/pc/productDetail.jsp?navId=H0,C1,C1007,C1017,P2064]
National semiconductor LMS485: [http://www.national.com/mpf/LM/LMS485.html]
National semiconductor DS75176B (used in Martin PAL 1200, Lite-Puter DX-625 and a cheap Eurolite DMX console) [http://www.national.com/mpf/DS/DS75176B.html]

=== Transmitter/receiver topologies ===
To avoid ground loops between equipment and improve reception performance, the transmitters and receivers for the DMX line must use a good combination of transmitter/receiver topologies. Some are not allowed, some are accepted with warning labels and some are preferred. See http://www.usitt.org/standards/DMX512_FAQ.html#FAQ_15 .

Transmitters should use "earth ground" as a reference for the positive/negative voltages that is put on the two data lines.
Receivers should be "isolated".

==The protocol==
'''A Universe''' contains 512 addresses and a single DMX line (cable) can only transmit one universe. I.e. a controller with two universes need two DMX lines (daisy chains including splitters). A universe is normally thought of as an address space (in the controller), the cables that transmits it and the equipment that receives it.

* The DMX signal is made up of a sequence - called a ''packet'' - which is sent over and over again (to increase robustness).
* It is up to the controller/transmitter to decide how many of the 512 values is sent. A shorter packet means faster cycles.
* A receiver must be set or programmed to an address it listens to. If a receiver listens to multiple addresses, the set one is the first. (It depends on implementation.)
* Multiple receiver can listen to the same address - the DMX system does not care.

'''A packet''' has the following sequence:
* Break
* Mark After Break (MAB)
* The ''"start code"'' frame (Sometimes called address 0) [http://www.esta.org/tsp/working_groups/CP/DMXAlternateCodes.php Alternate start codes]
* 1-512 ''slots/frames'' with the values of the channels. The first value is for address "1", the next for address 2 etc.
(Note: A packet must have a minimum length in time)

* A slot/frame contains the value for one address, has one start bit and two stop bits.
* The address number is not sent over the lines, so the receiver must count the received slots from the start of the sequence to find the wanted value.
* The ''start code'' is used to alter the meaning of the data bytes in the rest of the packet. The default is 0, and the remaining 255 values is rarely used (by definition 0 means dimmers, but is used for intelligent light as well).

''Note that some people and texts use the words frame and packet in the opposite sense than stated here.''

== Timings ==
The clock rate is 250 kHz so each symbol bit on the wire is 4 microseconds long (period time).

Symbol length is 4 +/- 0.08us for 245 - 255 k baud/s, with non-return-zero between symbol bits. To transmit 8 data bits it take 11 symbols because the use of one start bit and two stop bits around each data byte. Slot/address number is known by counting slots from the long packet break in the beginning of each packet.

The maximum packet rate is 44 updates/s if all 513 slots are transmitted (start code + 512 values), but can be higher if fewer slots are transmitted. If only packets only consists of a start code + 24 values, up to 830 updates/s can be made.

{|border=1
||'''Name''' || '''Tx requirement''' || '''Typical/suggested Tx''' || '''Rx requirement'''
|-
||Break (a space) (the packet start) || >= 92 us || 100-120 us (Ujjal) 176 us (DMX512-A-2004)|| >= 88 us
|-
||Mark after break (in packet start) || >= 8 us || 12 us (Ujjal) || 4 us – < 1 s backward compatible 8 us – < 1 s DMX512-A-2004
|-
||Slot/frame width || 44 us || 44 us || 44 us
|-
||Inter-slot/frame time Mark time between slots|| < 1 s || minimal || < 1 s
|-
||Mark before break (Idle time after packet)|| < 1 s || minimal || < 1 s
|-
||Break to Break time (DMX2512 packet length) || 1204 us – 1 s|| minimal|| 1196 us – 1.25 s
|}
The Rx req. column shows what a receiver must be able to handle of valid timings.

Note that the minimum length of "Mark after break" was doubled from 4 to 8 us in 1990, and receivers can be backward compatible by accepting the shortest time.

The slot time must be precise, or else the receiver should discard the whole packet, e.g. if the second stop bit is missing.

There must be at least one packet with start code=0 per second, and a receiving product must specify what happens when this time is exceeded.

Here is a nice overview of the different parts of a DMX packet with timings etc.: http://www.erwinrol.com/index.php?stagecraft/dmx.php.
These timing values matches the ones in the DMX standard from 2004.

Idle must be high level (mark level, "Mark before break".

As a receiver must handle varying "mark time between slots", it needs to synchronize to each start bit in each slot.

==Sources and additional reading==

[http://en.wikipedia.org/wiki/DMX_(lighting) Wikipedia article]

[http://www.rocketsciencecanada.com/rocketsciencecanada/Lighting/ControlProtocols.asp#dmx512 Thorough DMX description and a long list of good references to other sites and projects]. Much better than a Google search!

[http://www.epanorama.net/links/lights.html#dmx512 ePanorama] (thorough descriptions of most details, lots of links) 

[http://www.usitt.org/standards/DMX512.html USITT ] 
[http://www.dmx512-online.com/packt.html Ujjal's DMX512 Pages] (down-to-earth walk-through, also a good historical overview from before DMX ) 
[http://www.euro-pa.be/dmx.html The anatomy of DMX512] (a nice, short overview)

[http://www.erwinrol.com/index.php?stagecraft/dmx.php DMX timings by Erwin Rol] 
[http://www.theater-technisch-lab.nl/infrdmxe.htm An other DMX signal/cable description]

[http://www.alia.com.au/features/dmx.pdf History from mechanical dimming over analog lines, multiplexing, DMX and to ACN] in three pages.

See also:

* [[E1.31 | E1.31 - DMX over ACN]]
* [[RDM | RDM - Remote Device Management]]

[[Category:Definitions]]

Talk:DMX512-A

2009-12-09T21:26:43Z

90.185.54.180: clean-up

== connectors ==
The use of modular plugs like 8-position modular connector (8P8C or RJ45) or 6P4C (RJ11)? Is there any allowance for other than 8 position modular connectors?
Some product (cheap dimmers) have 6 position connectors (RJ11).

== Sender/receiver topologies ==
To avoid ground loops and improve reception performance, transmitters and/or receivers can be grounded/floating/non-isolated ???
http://www.usitt.org/standards/DMX512_FAQ.html#FAQ_15
There are different topologies, and not all will work together. There are no requirement for what topology to use in the DMX specification from 1990, so it was added to DMX512-A.

Transmitters should use "earth ground" as a reference for the positive/negative voltages that is put on the two data lines. If they don't, it must be clearly marked on the product and in the manual.
Receivers should be ...?

== Voltages ==

At http://www.dmx512-online.com/physl.html there is an example wit D1+ at +5V and D1- at -5V, and considering [http://focus.ti.com/lit/an/slla070c/slla070c.pdf page 12 in this document from TI] it is presumably a wrong interpretation.

[http://www.dmx512-online.com/physl.html This web page] cites RS485 as having a upper limit of +12/-7 V with respect to ground. This probably refers to common mode loading voltages that receivers must work with. I.e. one of the data wires is allowed to reach +12 or -7 V but the opposite wire must not be at the other extreme, but only differ by 6 V maximum.

== Debugging tips ==

Links to simple testers?

How can reverse polarity be detected?
* The break at the very beginning of a packet must be low
* If all transmitted data bytes have value zero, the DMX line should be low about 80 % of the time if there are no extra idle time between slots/frames or packets.

DMX512-A

2009-12-09T21:11:03Z

90.185.54.180: Moved things around

''This information is not complete.'' The purpose is to introduce the protocol and the details of a packet and maybe explain the required timing of the signal. --[[User:Beier|Beier]] 06:21, 28 January 2007 (PST)

The last version of the standard is called [http://usitt.org/ USITT] DMX512-A and it is maintained by [http://esta.org ESTA] since 1998. In 2004 it was made an ANSI standard too, named "E1.11, USITT DMX512-A" or "ANSI E1.11-2004". In 2008 it was revised [http://www.esta.org/tsp/news/newsdetails.php?newsID=291] .

DMX is characterized by its simplicity in how data are transferred from a controller to receiving equipment.

== Electrical ==
DMX is based on the balanced serial connection standard [http://en.wikipedia.org/wiki/EIA-485 EIA-485-A] (a.k.a RS485).
Only 5-pin XLR meets the standard (and products may meet the requirement by supplying adapters).
Since the revision in 1998 the cables itself are not specified in DMX512-A (so it can be specified in separate standards?)
In general the cable must fulfill the [http://en.wikipedia.org/wiki/EIA-485 EIA-485] requirements of 120 Ohms (around 250 kHz) shielded twisted pair. One transmitter must be connected to maximum 32 receivers.
* Termination resistor tolerance is 120 Ohm +5 % / -10 % (108 – 126 Ohm).
* Each receiver must not load the differential line with more than 125 pF.

=== Use of category 5 UTP or STP ===
Other cable types have been examined to determine how well they are for DMX usage (as loose cables or in fixed building installations). The last report more or less concludes that for fixed installations, unshielded twisted pair in [http://en.wikipedia.org/wiki/Category_5_cable CAT 5] is good enough, even when it is mixed with 120 Ohm cable meant for EIA-485. The pulses from reflections and general degradation is not significant and harmless. See the three parts at http://www.esta.org/tsp/working_groups/CP/DMXoverCat5.htm .

See also this point in USITT's DMX faq:
http://www.usitt.org/DMX512FAQ.aspx#a9
(old link is [http://www.usitt.org/standards/DMX512_FAQ.html#FAQ_08])

The cabling for DMX512-A should be described in the document called "BSR E1.27-1 -- Portable Control Cables for Use with USITT DMX512/1990 and E1.11 [DMX512-A]"

The 8-position modular connector is allowed in the DMX512-A as an alternate connector if there is not space enough for XLR5 or for fixed installations in "controlled access areas".
Pin-out:
{|border=1
||Pin || Function
|-
|1 || data 1+
|-
|2 || data 1-
|-
|3 || data 2+
|-
|6 || data 2-
|-
|4 || Not assigned
|-
|5 || Not assigned
|-
|7 || Data link common for data 1
|-
|8 || Data link common for data 1
|}

Both common wires are mandatory, and must have same potential in equipment sockets.

=== Transmitter/receiver topologies ===
To avoid ground loops between equipment and improve reception performance, the transmitters and receivers for the DMX line must use a good combination of transmitter/receiver topologies. Some are not allowed, some are accepted with warning labels and some are preferred. See http://www.usitt.org/standards/DMX512_FAQ.html#FAQ_15 .

Transmitters should use "earth ground" as a reference for the positive/negative voltages that is put on the two data lines.
Receivers should be "isolated".

==The protocol==
'''A Universe''' contains 512 addresses and a single DMX line (cable) can only transmit one universe. I.e. a controller with two universes need two DMX lines (daisy chains including splitters). A universe is normally thought of as an address space (in the controller), the cables that transmits it and the equipment that receives it.

* The DMX signal is made up of a sequence - called a ''packet'' - which is sent over and over again (to increase robustness).
* It is up to the controller/transmitter to decide how many of the 512 values is sent. A shorter packet means faster cycles.
* A receiver must be set or programmed to an address it listens to. If a receiver listens to multiple addresses, the set one is the first. (It depends on implementation.)
* Multiple receiver can listen to the same address - the DMX system does not care.

'''A packet''' has the following sequence:
* Break
* Mark After Break (MAB)
* The ''"start code"'' frame (Sometimes called address 0) [http://www.esta.org/tsp/working_groups/CP/DMXAlternateCodes.php Alternate start codes]
* 1-512 ''slots/frames'' with the values of the channels. The first value is for address "1", the next for address 2 etc.
(Note: A packet must have a minimum length in time)

* A slot/frame contains the value for one address, has one start bit and two stop bits.
* The address number is not sent over the lines, so the receiver must count the received slots from the start of the sequence to find the wanted value.
* The ''start code'' is used to alter the meaning of the data bytes in the rest of the packet. The default is 0, and the remaining 255 values is rarely used (by definition 0 means dimmers, but is used for intelligent light as well).

Note that some people and texts use the words frame and packet in the opposite sense than stated here.

== Timings ==
The clock rate is 250 kHz so each symbol bit on the wire is 4 microseconds long (period time).

Symbol length is 4 +/- 0.08us for 245 - 255 k baud/s, with non-return-zero between symbol bits. To transmit 8 data bits it take 11 symbols because the use of one start bit and two stop bits around each data byte. Slot/address number is known by counting slots from the long packet break in the beginning of each packet.

The maximum packet rate is 44 updates/s if all 513 slots are transmitted (start code + 512 values), but can be higher if fewer slots are transmitted. If only packets only consists of a start code + 24 values, up to 830 updates/s can be made.

{|border=1
||'''Name''' || '''Tx requirement''' || '''Typical/suggested Tx''' || '''Rx requirement'''
|-
||Break (a space) (the packet start) || >= 92 us || 100-120 us (Ujjal) 176 us (DMX512-A-2004)|| >= 88 us
|-
||Mark after break (in packet start) || >= 8 us || 12 us (Ujjal) || 4 us – < 1 s backward compatible 8 us – < 1 s DMX512-A-2004
|-
||Slot/frame width || 44 us || 44 us || 44 us
|-
||Inter-slot/frame time Mark time between slots|| < 1 s || minimal || < 1 s
|-
||Mark before break (Idle time after packet)|| < 1 s || minimal || < 1 s
|-
||Break to Break time (DMX2512 packet length) || 1204 us – 1 s|| minimal|| 1196 us – 1.25 s
|}
The Rx req. column shows what a receiver must be able to handle of valid timings.

Note that the minimum length of "Mark after break" was doubled from 4 to 8 us in 1990, and receivers can be backward compatible by accepting the shortest time.

The slot time must be precise, or else the receiver should discard the whole packet, e.g. if the second stop bit is missing.

There must be at least one packet with start code=0 per second, and a receiving product must specify what happens when this time is exceeded.

Here is a nice overview of the different parts of a DMX packet with timings etc.: http://www.erwinrol.com/index.php?stagecraft/dmx.php.
These timing values matches the ones in the DMX standard from 2004.

Idle must be high level (mark level, "Mark before break".

As a receiver must handle varying "mark time between slots", it needs to synchronize to each start bit in each slot.

==Sources and additional reading==

[http://en.wikipedia.org/wiki/DMX_(lighting) Wikipedia] 
[http://www.usitt.org/standards/DMX512.html USITT ] 
[http://www.dmx512-online.com/packt.html Ujjal's DMX512 Pages] (down-to-earth walk-through, also a good historical overview from before DMX ) 
[http://www.epanorama.net/links/lights.html#dmx512 ePanorama] (thorough descriptions of most details, lots of links) 
[http://www.euro-pa.be/dmx.html The anatomy of DMX512] (a nice, short overview) 
[http://www.erwinrol.com/index.php?stagecraft/dmx.php DMX timings by Erwin Rol]

[http://www.alia.com.au/features/dmx.pdf History from mechanical dimming over analog lines, multiplexing, DMX and to ACN] in three pages.

[http://www.theater-technisch-lab.nl/infrdmxe.htm An other DMX signal/cable description]

[http://www.rocketsciencecanada.com/rocketsciencecanada/Lighting/ControlProtocols.asp#dmx512 Thorough DMX description and a long list of good references to other sites and projects]. Much better than a google search!

See also:

* [[E1.31 | E1.31 - DMX over ACN]]
* [[RDM | RDM - Remote Device Management]]

[[Category:Definitions]]

RDM

2009-12-09T20:56:42Z

90.185.54.180: wiki links to DMX

RDM or Remote Device Management is an extension to [[DMX]] that allows for bi-directional communication with DMX devices.
RDM will enable features such as device discovery, status monitoring and remote configuration.

The same data link used for basic DMX is used bidirectional for RDM (i.e. link 2 in cables/connectors is still unused).

The [[DMX]] controller decides which device/fixture is allowed to send RDM data back to the controller. The Controller sends RDM commands by making a packet with start code 0xCC (instead of 0, which is used for the basic lighting control).

Each RDM enabled device is assigned a 6 byte UID comprising of a 2 byte manufacturers ID and a 4 byte serial number. It is used to identify all devices on a universe (enumeration process) and sending RDM commands to them, e.g. to set their DMX address from the DMX controller.

Official name: ANSI/ESTA E1.20, Entertainment Technology - Remote Device Management over USITT DMX512

External Links:

* http://www.rdmprotocol.org/

* http://en.wikipedia.org/wiki/RDM_(lighting)

[[Category:Definitions]]

RDM

2009-12-09T20:54:28Z

90.185.54.180: Mentioned the most important aspects of RDM in brief, link to wikipedia

RDM or Remote Device Management is an extension to DMX that allows for bi-directional communication with DMX devices.
RDM will enable features such as device discovery, status monitoring and remote configuration.

The same data link used for basic DMX is used bidirectional for RDM (i.e. link 2 is still unused)

The DMX controller decides which device/fixture is allowed to send RDM data back to the controller. The Controller sends RDM commands by making a packet with start code 0xCC (instead of 0, which is used for the basic lighting control).

Each RDM enabled device is assigned a 6 byte UID comprising of a 2 byte manufacturers ID and a 4 byte serial number. It is used to identify all devices on a universe (enumeration process) and sending RDM commands to them, e.g. to set their DMX address from the DMX controller.

Official name: ANSI/ESTA E1.20, Entertainment Technology - Remote Device Management over USITT DMX512

External Links:

* http://www.rdmprotocol.org/

* http://en.wikipedia.org/wiki/RDM_(lighting)

[[Category:Definitions]]

Other web sites

2009-12-09T20:20:20Z

90.185.54.180: added links to assembler code

= Forums or other information resources on the net =

http://www.blue-room.org.uk/wiki/Main_Page

http://thedmxwiki.com/ Has started, misc. terms explained, like CMY and RGB color mixing.

http://stagecraft.theprices.net/ The stagecraft mailing list, thousands of email threads per year! All technical stuff is discussed, from safety to cabling.

http://ww1.microchip.com/downloads/en/AppNotes/01076A.pdf Application note from Microchip on implementing a transmitter and receiver in a PIC microcontroller with assembler code.

If an example for Tx and Rx in assembler for AVR is needed, look here: http://www.hoelscher-hi.de/hendrik/english/demux.htm

''If you know a useful resource, related to lighting tech, put it here!''

[[Category:Articles]]

Talk:DMX512-A

2009-12-09T16:43:07Z

90.185.54.180: more cleaning, termination tolerance

== Timings ==
The clock rate is 250 kHz so each symbol bit on the wire is 4 microseconds long (period time).

Symbol length is 4 +/- 0.08us for 245 - 255 k baud/s, with non-return-zero between symbol bits. To transmit 8 data bits it take 11 symbols because the use of one start bit and two stop bits around each data byte. Slot/address number is known by counting slots from the long packet break in the beginning of each packet.

The maximum packet rate is 44 updates/s if all 513 slots are transmitted (start code + 512 values), but can be higher if fewer slots are transmitted. If only packets only consists of a start code + 24 values, up to 830 updates/s can be made.

{|border=1
||'''Name''' || '''Tx requirement''' || '''Typical/suggested Tx''' || '''Rx requirement'''
|-
||Break (a space) (the packet start) || >= 92 us || 100-120 us (Ujjal) 176 us (DMX512-A-2004)|| >= 88 us
|-
||Mark after break (in packet start) || >= 8 us || 12 us (Ujjal) || 4 us – < 1 s backward compatible 8 us – < 1 s DMX512-A-2004
|-
||Slot/frame width || 44 us || 44 us || 44 us
|-
||Inter-slot/frame time Mark time between slots|| < 1 s || minimal || < 1 s
|-
||Mark before break (Idle time after packet)|| < 1 s || minimal || < 1 s
|-
||Break to Break time (DMX2512 packet length) || 1204 us – 1 s|| minimal|| 1196 us – 1.25 s
|}
The Rx req. column shows what a receiver must be able to handle of valid timings.

Note that the minimum length of "Mark after break" was doubled from 4 to 8 us in 1990, and receivers can be backward compatible by accepting the shortest time.

The slot time must be precise, or else the receiver should discard the whole packet, e.g. if the second stop bit is missing.

There must be at least one packet with start code=0 per second, and a receiving product must specify what happens when this time is exceeded.

Here is a nice overview of the different parts of a DMX packet with timings etc.: http://www.erwinrol.com/index.php?stagecraft/dmx.php.
These timing values matches the ones in the DMX standard from 2004.

Idle must be high level (mark level, "Mark before break".

As a receiver must handle varying "mark time between slots", it needs to synchronize to each start bit in each slot.

== Use of category 5 UTP or STP ==
New cable types is used, and may be officially accepted.
http://www.usitt.org/DMX512FAQ.aspx#a9
(old link is [http://www.usitt.org/standards/DMX512_FAQ.html#FAQ_08])

The cabling for DMX512-A should be described in the document called "BSR E1.27-1 -- Portable Control Cables for Use with USITT DMX512/1990 and E1.11 [DMX512-A]"

A PDF shows the research and measurements that shows cat. 5 cable is good enough for DMX.

The use of modular plugs like 8-position modular connector (8P8C or RJ45) or 6P4C (RJ11)?

The 8-position modular connector is allowed in the DMX512-A as an alternate connector if there is not space enough for XLR5 or for fixed installations in "controlled access areas".
Pin-out:
{|border=1
||Pin || Function
|-
|1 || data 1+
|-
|2 || data 1-
|-
|3 || data 2+
|-
|6 || data 2-
|-
|4 || Not assigned
|-
|5 || Not assigned
|-
|7 || Data link common for data 1
|-
|8 || Data link common for data 1
|}

Both common wires are mandatory, and must have same potential in equipment sockets.

== Sender/receiver topologies ==
To avoid ground loops and improve reception performance, transmitters and/or receivers can be grounded/floating/non-isolated ???
http://www.usitt.org/standards/DMX512_FAQ.html#FAQ_15
There are different topologies, and not all will work together. There are no requirement for what topology to use in the DMX specification from 1990, so it was added to DMX512-A.

Transmitters should use "earth ground" as a reference for the positive/negative voltages that is put on the two data lines. If they don't, it must be clearly marked on the product and in the manual.
Receivers should be ...?

== More suggestions and info ==

Here is also a nice overview of the different parts of a DMX packet with timings etc.:
http://www.erwinrol.com/index.php?stagecraft/dmx.php

== Voltages ==

The power dissipation in the 120 Ohm terminating resistors depends on the differential voltage between the two data wires.
If the transmitter only makes a 5 V differential voltage, the power dissipation is P= U*U/R= 5*5/120 = 208 mW.

According to http://focus.ti.com/lit/an/slla070c/slla070c.pdf the maximum absolute differential voltage allowed by the EIA485 standard is 6 V.
This give the maximum power dissipation is P= U*U/R= 6*6/120 = 300 mW. So it is best to use 1/2 W resistors.

At http://www.dmx512-online.com/physl.html there is an example wit D1+ at +5V and D1- at -5V, and considering [http://focus.ti.com/lit/an/slla070c/slla070c.pdf page 12 in this document from TI] it is presumably a wrong interpretation.

[http://www.dmx512-online.com/physl.html This web page] cites RS485 as having a upper limit of +12/-7 V with respect to ground. This probably refers to common mode loading voltages that receivers must work with. I.e. one of the data wires is allowed to reach +12 or -7 V but the opposite wire must not be at the other extreme, but only differ by 6 V maximum.

Transceiver chips made for 5 V:
Linear Technology LTC485: http://www.linear.com/pc/productDetail.jsp?navId=H0,C1,C1007,C1017,P2064
National semiconductor LMS485: http://www.national.com/mpf/LM/LMS485.html
National semiconductor DS75176B (used in Martin PAL 1200, Lite-Puter DX-625 and a cheap Eurolite DMX console) http://www.national.com/mpf/DS/DS75176B.html

Termination resistor tolerance is 120 Ohm +5 % / -10 % (108 – 126 Ohm).

Each receiver must not load the differential line with more than 125 pF.

== Debugging tips ==

Links to simple testers?

How can reverse polarity be detected?
* The break at the very beginning of a packet must be low
* If all transmitted data bytes have value zero, the DMX line should be low about 80 % of the time if there are no extra idle time between slots/frames or packets.

Talk:DMX512-A

2009-12-09T16:28:41Z

90.185.54.180: removed obsolete text, it is already mentioned elsewhere

== Timings ==
The clock rate is 250 kHz so each symbol bit on the wire is 4 microseconds long (period time).

Frame rate is ??
Packet rate is typically around 44 Hz when all frames are sent.

== DMX Timing table ==

Symbol length is 4 +/- 0.08us for 245 - 255 k baud/s, with non-return-zero between symbol bits. To transmit 8 data bits it take 11 symbols because the use of one start bit and two stop bits around each data byte. Slot/address number is known by counting slots from the long packet break in the beginning of each packet.

The maximum packet rate is 44 updates/s if all 513 slots are transmitted (start code + 512 values), but can be higher if fewer slots are transmitted. If only packets only consists of a start code + 24 values, up to 830 updates/s can be made.

{|border=1
||'''Name''' || '''Tx requirement''' || '''Typical/suggested Tx''' || '''Rx requirement'''
|-
||Break (a space) (the packet start) || >= 92 us || 100-120 us (Ujjal) 176 us (DMX512-A-2004)|| >= 88 us
|-
||Mark after break (in packet start) || >= 8 us || 12 us (Ujjal) || 4 us – < 1 s backward compatible 8 us – < 1 s DMX512-A-2004
|-
||Slot/frame width || 44 us || 44 us || 44 us
|-
||Inter-slot/frame time Mark time between slots|| < 1 s || minimal || < 1 s
|-
||Mark before break (Idle time after packet)|| < 1 s || minimal || < 1 s
|-
||Break to Break time (DMX2512 packet length) || 1204 us – 1 s|| minimal|| 1196 us – 1.25 s
|}
The Rx req. column shows what a receiver must be able to handle of valid timings.

Note that the minimum length of "Mark after break" was doubled from 4 to 8 us in 1990, and receivers can be backward compatible by accepting the shortest time.

The slot time must be precise, or else the receiver should discard the whole packet, e.g. if the second stop bit is missing.

There must be at least one packet with start code=0 per second, and a receiving product must specify what happens when this time is exceeded.

Here is a nice overview of the different parts of a DMX packet with timings etc.: http://www.erwinrol.com/index.php?stagecraft/dmx.php.
These timing values matches the ones in the DMX standard from 2004.

Idle must be high level (mark level, "Mark before break".

As a receiver must handle varying "mark time between slots", it needs to synchronize to each start bit in each slot.

== Use of category 5 UTP or STP ==
New cable types is used, and may be officially accepted.
http://www.usitt.org/DMX512FAQ.aspx#a9
(old link is http://www.usitt.org/standards/DMX512_FAQ.html#FAQ_08)

The cabling for DMX512-A should be described in the document called "BSR E1.27-1 -- Portable Control Cables for Use with USITT DMX512/1990 and E1.11 [DMX512-A]"

A PDF shows the research and measurements that shows cat. 5 cable is good enough for DMX.

The use of modular plugs like 8-position modular connector (8P8C or RJ45) or 6P4C (RJ11)?

The 8-position modular connector is allowed in the DMX512-A as an alternate connector if there is not space enough for XLR5 or for fixed installations in "controlled access areas".
Pin-out:
{|border=1
||Pin || Function
|-
|1 || data 1+
|-
|2 || data 1-
|-
|3 || data 2+
|-
|6 || data 2-
|-
|4 || Not assigned
|-
|5 || Not assigned
|-
|7 || Data link common for data 1
|-
|8 || Data link common for data 1
|}

Both common wires are mandatory, and must have same potential in equipment sockets.

== Sender/receiver topologies ==
To avoid ground loops and improve reception performance, transmitters and/or receivers can be grounded/floating/non-isolated ???
http://www.usitt.org/standards/DMX512_FAQ.html#FAQ_15
There are different topologies, and not all will work together. There are no requirement for what topology to use in the DMX specification from 1990, so it was added to DMX512-A.

Transmitters should use "earth ground" as a reference for the positive/negative voltages that is put on the two data lines. If they don't, it must be clearly marked on the product and in the manual.
Receivers should be ...?

== More suggestions and info ==

Here is also a nice overview of the different parts of a DMX packet with timings etc.:
http://www.erwinrol.com/index.php?stagecraft/dmx.php

== Voltages ==

The power dissipation in the 120 Ohm terminating resistors depends on the differential voltage between the two data wires.
If the transmitter only makes a 5 V differential voltage, the power dissipation is P= U*U/R= 5*5/120 = 208 mW.

According to http://focus.ti.com/lit/an/slla070c/slla070c.pdf the maximum absolute differential voltage allowed by the EIA485 standard is 6 V.
This give the maximum power dissipation is P= U*U/R= 6*6/120 = 300 mW. So it is best to use 1/2 W resistors.

At http://www.dmx512-online.com/physl.html there is an example wit D1+ at +5V and D1- at -5V, and considering [http://focus.ti.com/lit/an/slla070c/slla070c.pdf page 12 in this document from TI] it is presumably a wrong interpretation.

[http://www.dmx512-online.com/physl.html This web page] cites RS485 as having a upper limit of +12/-7 V with respect to ground. This probably refers to common mode loading voltages that receivers must work with. I.e. one of the data wires is allowed to reach +12 or -7 V but the opposite wire must not be at the other extreme, but only differ by 6 V maximum.

Transceiver chips made for 5 V:
Linear Technology LTC485: http://www.linear.com/pc/productDetail.jsp?navId=H0,C1,C1007,C1017,P2064
National semiconductor LMS485: http://www.national.com/mpf/LM/LMS485.html
National semiconductor DS75176B (used in Martin PAL 1200, Lite-Puter DX-625 and a cheap Eurolite DMX console) http://www.national.com/mpf/DS/DS75176B.html

a but the spec says that the differential maximum from transmitters is 6 V, according to

== Debugging tips ==

Links to simple testers?

How can reverse polarity be detected?
* The break at the very beginning of a packet must be low
* If all transmitted data bytes have value zero, the DMX line should be low about 80 % of the time if there are no extra idle time between slots/frames or packets.

Talk:DMX512-A

2009-12-09T16:25:43Z

90.185.54.180: Added and corrected some more details.

== Timings ==
The clock rate is 250 kHz so each symbol bit on the wire is 4 microseconds long (period time).

Frame rate is ??
Packet rate is typically around 44 Hz when all frames are sent.

== RDM protocol additions ==
The name of the standard is: ANSI/ESTA 1.20, Entertainment Technology - Remote Device Management over USITT DMX512
???
Mark (beginning of frames)
Mark After Break (beginning of frames)

Mark time between packet
Mark time between frames

DMX Timing table

Symbol length is 4 +/- 0.08us for 245 - 255 k baud/s, with non-return-zero between symbol bits. To transmit 8 data bits it take 11 symbols because the use of one start bit and two stop bits around each data byte. Slot/address number is known by counting slots from the long packet break in the beginning of each packet.

The maximum packet rate is 44 updates/s if all 513 slots are transmitted (start code + 512 values), but can be higher if fewer slots are transmitted. If only packets only consists of a start code + 24 values, up to 830 updates/s can be made.

{|border=1
||'''Name''' || '''Tx requirement''' || '''Typical/suggested Tx''' || '''Rx requirement'''
|-
||Break (a space) (the packet start) || >= 92 us || 100-120 us (Ujjal) 176 us (DMX512-A-2004)|| >= 88 us
|-
||Mark after break (in packet start) || >= 8 us || 12 us (Ujjal) || 4 us – < 1 s backward compatible 8 us – < 1 s DMX512-A-2004
|-
||Slot/frame width || 44 us || 44 us || 44 us
|-
||Inter-slot/frame time Mark time between slots|| < 1 s || minimal || < 1 s
|-
||Mark before break (Idle time after packet)|| < 1 s || minimal || < 1 s
|-
||Break to Break time (DMX2512 packet length) || 1204 us – 1 s|| minimal|| 1196 us – 1.25 s
|}
The Rx req. column shows what a receiver must be able to handle of valid timings.

Note that the minimum length of "Mark after break" was doubled from 4 to 8 us in 1990, and receivers can be backward compatible by accepting the shortest time.

The slot time must be precise, or else the receiver should discard the whole packet, e.g. if the second stop bit is missing.

There must be at least one packet with start code=0 per second, and a receiving product must specify what happens when this time is exceeded.

Here is a nice overview of the different parts of a DMX packet with timings etc.: http://www.erwinrol.com/index.php?stagecraft/dmx.php.
These timing values matches the ones in the DMX standard from 2004.

Idle must be high level (mark level, "Mark before break".

As a receiver must handle varying "mark time between slots", it needs to synchronize to each start bit in each slot.

== Use of category 5 UTP or STP ==
New cable types is used, and may be officially accepted.
http://www.usitt.org/DMX512FAQ.aspx#a9
(old link is http://www.usitt.org/standards/DMX512_FAQ.html#FAQ_08)

The cabling for DMX512-A should be described in the document called "BSR E1.27-1 -- Portable Control Cables for Use with USITT DMX512/1990 and E1.11 [DMX512-A]"

A PDF shows the research and measurements that shows cat. 5 cable is good enough for DMX.

The use of modular plugs like 8-position modular connector (8P8C or RJ45) or 6P4C (RJ11)?

The 8-position modular connector is allowed in the DMX512-A as an alternate connector if there is not space enough for XLR5 or for fixed installations in "controlled access areas".
Pin-out:
{|border=1
||Pin || Function
|-
|1 || data 1+
|-
|2 || data 1-
|-
|3 || data 2+
|-
|6 || data 2-
|-
|4 || Not assigned
|-
|5 || Not assigned
|-
|7 || Data link common for data 1
|-
|8 || Data link common for data 1
|}

Both common wires are mandatory, and must have same potential in equipment sockets.

== Sender/receiver topologies ==
To avoid ground loops and improve reception performance, transmitters and/or receivers can be grounded/floating/non-isolated ???
http://www.usitt.org/standards/DMX512_FAQ.html#FAQ_15
There are different topologies, and not all will work together. There are no requirement for what topology to use in the DMX specification from 1990, so it was added to DMX512-A.

Transmitters should use "earth ground" as a reference for the positive/negative voltages that is put on the two data lines. If they don't, it must be clearly marked on the product and in the manual.
Receivers should be ...?

== More suggestions and info ==

Here is also a nice overview of the different parts of a DMX packet with timings etc.:
http://www.erwinrol.com/index.php?stagecraft/dmx.php

== Voltages ==

The power dissipation in the 120 Ohm terminating resistors depends on the differential voltage between the two data wires.
If the transmitter only makes a 5 V differential voltage, the power dissipation is P= U*U/R= 5*5/120 = 208 mW.

According to http://focus.ti.com/lit/an/slla070c/slla070c.pdf the maximum absolute differential voltage allowed by the EIA485 standard is 6 V.
This give the maximum power dissipation is P= U*U/R= 6*6/120 = 300 mW. So it is best to use 1/2 W resistors.

At http://www.dmx512-online.com/physl.html there is an example wit D1+ at +5V and D1- at -5V, and considering [http://focus.ti.com/lit/an/slla070c/slla070c.pdf page 12 in this document from TI] it is presumably a wrong interpretation.

[http://www.dmx512-online.com/physl.html This web page] cites RS485 as having a upper limit of +12/-7 V with respect to ground. This probably refers to common mode loading voltages that receivers must work with. I.e. one of the data wires is allowed to reach +12 or -7 V but the opposite wire must not be at the other extreme, but only differ by 6 V maximum.

Transceiver chips made for 5 V:
Linear Technology LTC485: http://www.linear.com/pc/productDetail.jsp?navId=H0,C1,C1007,C1017,P2064
National semiconductor LMS485: http://www.national.com/mpf/LM/LMS485.html
National semiconductor DS75176B (used in Martin PAL 1200, Lite-Puter DX-625 and a cheap Eurolite DMX console) http://www.national.com/mpf/DS/DS75176B.html

a but the spec says that the differential maximum from transmitters is 6 V, according to

== Debugging tips ==

Links to simple testers?

How can reverse polarity be detected?
* The break at the very beginning of a packet must be low
* If all transmitted data bytes have value zero, the DMX line should be low about 80 % of the time if there are no extra idle time between slots/frames or packets.

ArtNet

2009-12-09T14:15:00Z

90.185.54.180: added wiki links, removed spelling errors

[[Category:Definitions]]

ArtNet is a protocol for sending DMX data over IP networks developed by [[Artistic Licence]]. In order to understand ArtNet it helps to know a bit about DMX and IP, so here it goes....

==What is DMX?==

[[DMX]] is a standard for controlling theater equipment (mainly lighting). In a theater, there are normally large numbers of lights, that have to be turned on and off independently. One solution to this is to wire the theater like a house and have a desk of on/off switches with a mains cable running to each light.

There are a couple of issues with this however. First, mains cables are relatively thick, even with 20 lights and 20 cables, a lot of wire is involved. Secondly, if we ever wanted to move the desk, we'd have to run a new wire for every light which is most theaters would be a horrendous job. Finally, doing the same thing many times isn't the way we engineers like to work :)

So, instead of a cable from the desk to every light. why not put all the mains switching gear near the lights and run a low voltage control signal from the desk? Sounds good? Well thats exactly what DMX does.

DMX is a serial protocol, so it sends data one bit at a time over the wire. Each DMX cable can control up to 512 channels (for now, each channel is a light) and each channel takes a value between 0 and 255. If conventional lights are being used, each light occupies a single channel and the value of the channel is the intensity of the light (0 = off, 255 = full).

In a [[DMX]] cable, only 3 of the 5 pins are used (signal +, signal -, and ground).

A DMX network is formed in a daisy chain fashion, so one device is the source (most often the lighting control console) and the other devices are the receivers. Each receiver has a preset address, which corresponds to the channels of DMX data (from 1 to 512) that it is interested in.

==What are IP Networks?==

Like DMX, IP is a protocol. Where as DMX connects lighting equipment, IP was designed to connect computers. For the scope of this discussion, IP operates on top of another protocol called Ethernet. Cables are generally CAT5 and have RJ45 jacks on the end, similar to phone jacks.

Ethernet is wired in a star fashion (extended star to be precise), so an Ethernet network looks a bit like this:

==ArtNet and DMX==

Back to ArtNet. ArtNet then is a way of sending DMX information over IP networks. So what are the advantages ?

* An ethernet cable can carry a lot more information than a DMX cable (Part of my work is to identify exactly how much is "a lot").
* Hardware for ethernet networks is much cheaper than DMX networks
* IP is not tied to a single physical medium, this means it's as easy to send the DMX data via wireless links as it is to send it down wireless. Coupled with point two, this means we can have very low cost wireless DMX links.
* Continuing from point three, this means that it's also easy to send DMX data over the Internet. Ever wanted to control your lights from a suburb away?
* ArtNet supports bi-directional communication, this means that nodes can send information back to the controllers (DMX also supports this via [[RDM]], but you may have to upgrade your equipment).

OLA on Linux

2009-11-22T09:52:17Z

90.185.54.180: better spacing

=Installing OLA on Linux From GIT/Archive=

This describes how to get OLA working on a Linux system.

==Checkout or Download an Archive==

git clone http://www.nomis52.net/git/lla

If you don't have it yet, install '''git''' using your distro's package manager.

==Install libraries==

You need a couple of libraries installed for everything to work correctly. Some of these are available as packages in most distros but others need to be downloaded.

First up we'll need '''microhttpd''' for the embedded web server (Note: you'll need version >= 0.4.0):

-> [ftp://ftp.gnu.org/gnu/libmicrohttpd/ ftp://ftp.gnu.org/gnu/libmicrohttpd/]

Then you will need '''libcppunit-dev''' and '''libcppunit'''.

Debian users can install them with apt:

apt-get install libcppunit-dev libcppunit-1.12-1 uuid-dev

Next, you need the '''Protocol Buffers''' from Google (BSD license). Most likely, you will need to download and build them yourself:

-> [http://code.google.com/p/protobuf/ http://code.google.com/p/protobuf/]

Debian (and Ubuntu) users can, in some cases, use the following packets (not yet in stable):
libprotobuf2 (libprotobuf3), libprotobuf-dev, protobuf-compiler

Then, build '''CTemplate''' (another Google goodie):

-> [http://code.google.com/p/google-ctemplate/ http://code.google.com/p/google-ctemplate/]

Finally run ldconfig as root to pick up the new libraries

ldconfig

==Configure==

If you checked out the sources from git, you'll need to run

autoreconf -i

After that run

./configure

==Building & Testing==

Build
make

If you get an error like the following:

/bin/sh ./libtool --tag=CC --mode=compile gcc -DHAVE_CONFIG_H -I. -I/opt/local/var/macports/software/protobuf-cpp/2.0.3_0/opt/local/include/ -g -O2 -c -o ltdl.lo ltdl.c
./libtool: line 464: CDPATH: command not found
/Users/simonn/lighting/lla/libltdl/libtool: line 464: CDPATH: command not found
/Users/simonn/lighting/lla/libltdl/libtool: line 1142: func_opt_split: command not found
libtool: Version mismatch error. This is libtool 2.2.6, but the
libtool: definition of this LT_INIT comes from an older release.
libtool: You should recreate aclocal.m4 with macros from libtool 2.2.6
libtool: and run autoconf again.

Your system uses a different version of libtool. Run:

libtoolize --ltdl -c -f

and then start from the autoreconf step again.

Run the tests
make check

And install OLA
sudo make install
sudo ldconfig

OLA on Linux

2009-11-22T09:49:54Z

90.185.54.180: /* Install libraries */

DMX 4 Linux

2009-06-11T10:46:36Z

90.185.54.180: Brought it up to date, more links to related software

Link: http://llg.cubic.org/dmx4linux/ 
{{Features|linux=yes|free=yes}}

DMX 4 Linux has been the de-facto library for communicating with DMX devices under Linux.
Supporting over 14 DMX interfaces including PCI, USB and parallel port models, the DMX 4 Linux architecture is easily extensible.

Alternatives include the driver framework [[LLA] (with many DMX over IP protocols) and the controller app [[QLC]] that directly supports [[Enttec]] [[Open DMX USB]] [[Anyma uDMX]] , and with a special kernel module the [[Rodin1]].

''' DMX 4 Linux 2.6 Release'''
Development snapshots for 2.6 kernels from the dmx4linux developers are [http://www.cubic.org/~michael/dmx4linux-daily/ here]

Bastien Andres has made an unofficial release of [[DMX 4 Linux]] for the 2.6 series of kernels. A number of drivers have been modified to compile cleanly on 2.6 and the build system has also been cleaned.

Some drivers do not compile or are incomplete, see the STATUS_BA file in the archive for more details. Sources available [http://www.nomis52.net/data/sources/dmx4linux-2.9-ba-061001.tgz here]

The latest official release is 2.6.1 from April 2008 [ftp://ftp.cubic.org/pub/llg/dmx4linux-2.6.1.tar.gz].

[[Category:Drivers / Libraries]]

DMX512-A

2009-06-10T13:43:34Z

90.185.54.180: added link, slot=frame

DMX512-A

2009-06-07T22:40:40Z

90.185.54.180: New cable info

Talk:Q Light Controller (QLC)

2009-05-04T21:59:02Z

90.185.54.180: New page: The page could mention interesting features. The following is take partly from the old web site at qlc.sf.net: Features * Device-oriented interface * Control one DMX Universe, up to 512 ...

The page could mention interesting features.

The following is take partly from the old web site at qlc.sf.net:
Features

* Device-oriented interface
* Control one DMX Universe, up to 512 DMX or Analog channels
* Define your own fixtures with the device class editor™
* Create fast changing or smoothly fading scenes, chasers and sequences
* Easy programming of moving lights through a pattern generator
* Conjure your favourite lighting desk layout with the virtual console™

Q Light Controller (QLC)

2009-05-04T21:48:12Z

90.185.54.180: made some updates regarding v. 3

Link: https://sourceforge.net/projects/qlc/ 
{{Features|linux=yes|osx=yes|win=yes|tx=yes|free=yes}}
[[Image:Qlc-2.4.png|right]]

QLC is a lighting controller for Linux. Started as a university project by Heikki Junnila, it has now evolved with an active development community.
The latest version adds support for external fader devices such as the Behringer BCF-2000. In 2009 it was released for Mac Os and Windows also.

DMX output is provided using:
* the driver system [[LLA]] (via a plugin to QLC), allowing DMX ouput using various DMX over IP protocols. (for Linux and Mac OS, not yet ported to windows)
* the DMX 4 Linux library (Linux Only)
* the Peperoni [[USBDMX21]] interface, plugin named usbdmx (Linux and ?)
* the Enttec [[Open DMX USB]] (or other hardware with just a FTDI chip), plugin name is FTDI DMX (Windows and Mac OS?)

At the moment there are most drivers for Linux and fewest for Windows. In v. 3.0 the plugin for LLA is not included/enabled per default

Related Tutorials:
* [[LLA and Q Light Controller Ubuntu Tutorial]]

Related Products:
* [[DMX 4 Linux]]
* Peperoni [[USBDMX21]]
* [[LLA]]

[[Category:Controllers]]

Talk:DMX512-A

2009-03-31T20:33:10Z

90.185.54.180: /* More suggestions and info */

Talk:LLA, OpenDMX USB and Q Light Controller Tutorial

2009-01-09T10:03:44Z

90.185.54.180: New section: why run llad as root?

Is this tutorial minded on a specific interface?
That's what the title says :) Although the procedure is similar for other devices.

What is "Erwin Rol's driver" meant to do? (is it to support some specific hardware that is not supported directly by LLA?)
LLA uses the driver to support the enttec open dmx.

The first time QLC is run int the tutorial, it is run as root. Why?
Good question - this should be removed. I think it was probably added to get around any permissions problems with the devices but this isn't the way to solve the problem.

It would be nice if the intro explained what you can achieve over a default installation of LLA+ QLC from the repositories.

== Problems regarding install under kubuntu ==

Hi there!

I've got a problem while trying to follow the install tutorial. At first, not the device /dev/dmx is created but /dev/dmx0

Secondly, when I try to start the llad, the daemon aborts in the artnet region:

Failed to open lla-artnet.conf: No such file or directory
terminate called after throwing an instance of 'std::logic_error'
what(): basic_string::_S_construct NULL not valid
Aborted

Any idea what this could be? Thanks, CJ --[[User:79.245.72.170|79.245.72.170]] 15:18, 1 June 2008 (PDT)

== Solution found ? ==

Hi CJ,

Did you manage to get it working in the mean time ?

I have exactly the same problem.

Regards,

Bruno

== Same problem ==

I had tried to compile it from source or to use the debian packages.
but in both situations, I get the same problems:

lla_plugin_info
lla_plugin_info: error while loading shared libraries: liblla.so.1: cannot open shared object file: No such file or directory

OR

llad -d 3 -f -s
Failed to open lla-universes.conf: No such file or directory
Loaded plugin StageProfi Plugin
Loaded plugin UsbPro Plugin
Loaded plugin Dummy Plugin
Loaded plugin OpenDmx Plugin
Loaded plugin ArtNet Plugin
Trying to start StageProfi Plugin
Failed to open lla-stageprofi.conf: No such file or directory
StageProfiWidget: could not connect Connection refused
StageProfiPlugin: failed to connect to StageProfi Device
Started StageProfi Plugin
Trying to start UsbPro Plugin
Failed to open lla-usbpro.conf: No such file or directory
UsbProPlugin: failed to connect to /dev/ttyUSB0
Started UsbPro Plugin
Trying to start Dummy Plugin
Failed to open lla-dummy.conf: No such file or directory
Installed device
Started Dummy Plugin
Trying to start OpenDmx Plugin
Failed to open lla-opendmx.conf: No such file or directory
Started OpenDmx Plugin
Trying to start ArtNet Plugin
Failed to open lla-artnet.conf: No such file or directory
terminate called after throwing an instance of 'std::logic_error'
what(): basic_string::_S_construct NULL not valid
Aborted

== works for me now! ==

first, you have to use an older version of lla (0.2.1).
second, when you get the error

error while loading shared libraries: liblla.so.1: cannot open shared object file: No such file or directory

you have to set symbolic linksfrom the newer lib-path (usr/local/lib) to tne older path (usr/lib)

for example:
ln -s /usr/local/lib/liblla.so.1 /usr/lib/liblla.so.1

Greets
Claudio

== This is what I did to make it work ==

So I had the same error with Failed to open lla-artnet.conf,

I found that in ~/.lla/ there was only one config file, and no lla-artnet.conf

so I booted up the live cd and explored in /root/.lla/ is the .conf files for lla I made a tar of that directory and copied it,
and extracted and it worked,

anyways here is a link to the lla config files [http://texaskun.endofnet.com/lla.tar]

Jason

== why run llad as root? ==

In the section "put it all togethere", all the lla commands are run with (graphical) sudo, but is this necessary, even with Erwin Rol's driver for the Linux kernel? Can someone with a Enttec Open DMX interface check this?

Talk:Rodin1

2008-11-13T07:39:12Z

90.185.54.180: more info

Is this the one, which have direct support from QLC ???
In that case, there are all needed drivers available for Linux (and Mac in the development version of QLC)

Talk:LLA, OpenDMX USB and Q Light Controller Tutorial

2007-08-12T14:00:19Z

90.185.54.180: Questions/suggestions

Is this tutorial minded on a specific interface?
What is "Erwin Rol's driver" meant to do? (is it to support some specific hardware that is not supported directly by LLA?)

The first time QLC is run int the tutorial, it is run as root. Why?

It would be nice if the intro explained what you can achieve over a default installation of LLA+ QLC from the repositories.