How to import fixtures into D-PRO when no Internet connection is available

Question: How do I manually import fixture definitions from the online fixture editor into D-PRO, when the D-PRO computer does not have internet connectivity?

Currently, the only way to import fixtures into D-PRO is via the Patch Window, and this requires an internet connection (as it reads its data directly from the online fixture library).

A simple workaround is:

  • Install the D-PRO demo version on another computer with Internet connectivity.
  • Import the required fixtures into the demo (via the Patch Window)
  • Copy the Fixtures.dsf database file from the demo installation onto your real D-PRO installation.

The Fixtures.dsf file is a single database file that contains the entire D-PRO fixture library on that computer. It is located here:

OS X

  • Macintosh HD:/Library/Application Support/ENTTEC/D-Pro/Fixtures.dsf

Windows (32 bit)

  • C:/Program Files/ENTTEC/D-Pro (full version)/Fixtures.dsf
  • C:/Program Files/ENTTEC/D-Pro (2U version)/Fixtures.dsf

Windows (64 bit)

  • C:/Program Files (x86)/ENTTEC/D-Pro (full version)/Fixtures.dsf
  • C:/Program Files (x86)/ENTTEC/D-Pro (2U version)/Fixtures.dsf

How do I create a new fixture for use with DMXIS or D-PRO?

Use the online fixture editor

The easiest solution is to use the DMXIS online fixture editor. This public fixture database is an easy way to create fixture definitions for use in both DMXIS and D-PRO, and to download fixtures already created by other DMXIS/D-PRO users.

Simply go to fixtures.dmxis.com and create an account. Then you can log in and download or create fixtures for both DMXIS and D-PRO. More help and a tutorial video is available on the fixture editor page.

D-PRO fixtures

Currently, the only way to create an import a new fixture into D-PRO is via the online fixture editor (see above). Fixtures can be imported into D-PRO directly from the Patch window.

DMXIS fixtures

Manually create a fixture file

If you do not want to use the online editor, you can manually create the fixture file in a text editor. Fixture files must be saved as UNIX format. Most OS X editors save in this format by default, On Windows, Crimson Editor is a good choice.

Installing a new fixture file

Once you have a new fixture file (either downloaded from the online editor or created by hand) it must be saved into the DMXIS fixture library folder:

  • Windows: C:/Program Files (x86)/ENTTEC/DMXIS/DmxLibrary/
  • OS X : /Library/Application Support/ENTTEC/DMXIS/DmxLibrary/

The DmxLibrary folder contains a subfolder for each manufacturer. You can copy your own fixture files into to any existing subfolder, or create your own subfolder (e.g. “DmxLibrary/Bobs Fixtures”).

Fixture file internal format

Each DMXIS fixture file contains a simple list of channels. Each channel in turn contains a number of ranges covering 0-255 (the range of possible DMX values).

For example, a 3 channel fixture with Pan/Tilt/Speed channels might look like this:

Pan
V,0,255,
Tilt 
V,0,255, 
Speed 
V,0,255,
  • Each range contains the fields type, min, max, label
  • Type can be V (variable), S (static), D (dimmer) or B (blackout)
  • Variable ranges are displayed as a percentage under the DMXIS slider
  • Static ranges only display a label under the DMXIS slider.
  • Only Dimmer ranges will react to the DMXIS Master Level control.
  • Blackout values are automatically loaded for that fixture when the DMXIS Master Level control is set to minimum.
  • If the label is blank (as above) we only see a percentage displayed under the fader.
  • Static ranges always need a label (or you will see an empty label uder the slider!)

You can mix static & variable ranges in one channel. This is necessary, as manufacturers often squeeze lots of features into a single channel:

Gobo
S,0,30,Closed 
S,31,60,Circle 
S,61,90,Tunnel,
S,91,120,Open, 
V,121,255,Spin

My DMX lighting fixtures are misbehaving. Help!

If you find that your lighting fixtures are not responding reliably to commands from your DMX controller (be it DMXIS, D-Pro, Show Buddy or any other lighting controller) there are a number of things you can check.

The first thing to realise is this – DMX hardware problems are horribly difficult to diagnose. DMX communication is a very simplistic thing, with absolutely no error correction. When things go bad, they go bad in a confusing manner:

  • A poor quality cable connecting two fixtures might cause intermittent faults with a completely different fixture.
  • Changing the order of your fixtures could move the problem around randomly. An intermittent connection in a connector might only show up a problem once in a 3 hour show, as the room heats up.
  • Cheaply made fixtures might throw out interfere which causes other fixtures to misbehave – yet those fixtures will behave perfectly when connected alone.

Murphy’s Law dictates that these problems will hit you 5 minutes before showtime. So with this in mind, there are a few important guidelines which I recommend you observe.

Don’t use cheap mic cables to connect your lights. Please.

You will read many articles and forum posts from people who swear that they have “never had a problem using mic cables” and that “overpriced DMX cables are just a rip-off”. But the fact is that mic cable and DMX cable is quite different, and the difference becomes more significant as your cable runs increase in length.

DMX is a digital signal, and a long run of cheap mic cable will smudge out the nice sharp digital edges – to the point where  fixtures have difficulty in distinguishing the offs from the ons. DMX cable is designed to carry a digital signal and does not do this (primarily, for the tech geeks out there, due to the lower capacitance of DMX cable).

Also, beware of using really cheap cables sourced from unknown retailers over the Internet. Or if you do, inspect the workmanship INSIDE the connectors yourself before taking them out on a gig. See the picture below, this is the inside of a free DMX cable supplied to me with a brand name fixture from a reputable retailer. Sometimes, cheap cables are cheap for a reason.

Inside cheap dmx cable

My personal opinion is that if you’ve spent hundreds or thousands on your lighting rig, it makes no sense to risk the inevitable problems that cheap cabling could bring you.

Take care of your cables and test them regularly.

Learn how to coil your cables properly (Google for videos on “cable over under”) and don’t tie them in a big knot when you load out at the end of a gig.

Inspect your cables regularly to check for wear & tear, especially at the connectors.

An XLR cable tester box is an invaluable investment for anyone wiring up PAs or lighting rigs on a regular basis. With an XLR tester, you can quickly check a cable for breaks, shorts and – very usefully – intermittent faults.

Have you properly terminated your DMX line?

The final fixture in your DMX chain must be fitted with a DMX terminator. This is simply an XLR connector containing a single resistor, and it prevents reflections of the DMX signal from travelling back up the DMX line, causing errors. It is particularly important to fit a terminator of your DMX cable run is long (over a hundred feet or so).

Again, you can read plenty of people who say that their rig has always worked perfectly without a terminator. But they’re probably just lucky, and one day – eventually – the DMX monster will bite them in the backside.

Clashing fixtures

So, you’ve checked your cabling and terminated properly, but your fixtures are still misbehaving. You might now have a more complex issue with your rig.

Not all fixtures are made equal. Many cheaper fixtures are developed to incredibly tight budgets, and some manufacturers won’t a spend a lot of time or money in testing, making sure that their fixture [a] conforms to the DMX specification and [b] works well in a variety of rigs with other fixtures.

Consequently, it’s quite common to find that when you add a new fixture to your rig, it causes interference and problems with the others. Again, these problems are incredibly hard to diagnose, because often the fixture causing the problem is not the one that exhibits the fault.

D-split DMX splitter

In cases like this, a DMX splitter is your friend. A splitter box takes one DMX input (from your controller) and splits it into a number of electrically independent DMX outputs. You then hook up the problem fixtures to one output, and the rest of your rig to another. Problem solved. Splitters also make it easier to route your DMX cabling around the stage. Two things to remember:

  • Each chain of fixtures connected to a splitter outout need its own terminator plug (as discussed above)
  • Don’t attempt to use a simple audio Y-cable to split a DMX chain into two branches, THIS WILL NOT WORK.

Controller issues

If you’ve ran through all the above checks, and you still have reliability problems with some fixtures, it’s time to investigate if your controller is causing the problem. First, take ONE fixture that is misbehaving, connect it directly to your controller with a short DMX cable and terminate it.

Now, if this single fixture still misbehaves, it’s possible that the controller is transmitting DMX data too quickly. Some fixtures – especially cheaper one – are not engineered to cope with the full 40Hz update rates that the DMX protocol supports. In this case, you can try lowering the transmit rate of your control to say 20-25Hz.

DMXIS, Show Buddy & D-Pro users with Enttec hardware can do this using the Enttec DMX-Pro Manager utility.

Summary

This is just a list of the most common & easy to resolve causes of fixture problems on a DMX lighting rig. While not an exhaustive list of everything that can go wrong, these are certainly the first things you should check out before deciding whether a fixture is actually defective.

Dave Brown
db audioware

DMXIS error “FTDI serial driver is blocking DMXIS communication!”

UPDATE: this utility is no longer supported, and will not be updated to work with OS X 10.11. DMXIS and D-Pro now support the standard Apple FTDI driver. However, we will leave this page live in case anyone can make use of the utility on OS 10.10 or older.

If you see the error “FTDI serial driver is blocking DMXIS communication” when running DMXIS, it means that you have an incompatible driver installed on your Mac. You must disable this serial driver in order to enable DMXIS communications, using this simple utility (click to download)

OS X FTDI driver control1.0.4

What does this utility do?

This utility will temporarily disable any serial FTDI driver installed on your computer, which in turn allows applications built with FTDI’s standard D2XX driver to run as normal.

Requirements

You must be running OS X version 10.8-10.10. This utility does not support OS X 10.11 (El Capitan). New 10.11 compatible releases of DMXIS and D-Pro will be available shortly.

You must be logged in as a user with administrator rights (verify in System Preferences > Users & Groups) and your account must have a non-blank password (see http://support.apple.com/kb/PH13861).

Version History

  • V1.0.0. Initial release. Controls the OS X 10.9 Mavericks FTDI driver
  • V1.0.1. Extended to control the optional COM driver from FTDI.
  • V1.0.2. Added OS X 10.6 compatability. Signed app to pass OS X Gatekeeper
  • V1.0.3. Fixed to work following OS X upgrades
  • V1.0.4. Fixed to work with latest FTDI COM driver V2.3.0

My lightshow doesn’t play back accurately, and some events don’t play at all

The problem – bad timing

You have programmed some fast changes into your DMX light show, for example to follow the beat of a song. But your lights seem to react sluggishly, and sometimes the lights seem to skip a beat.

The bottom line

The DMX protocol is not designed to handle very fast lighting changes, and you cannot make your lighting rig strobe accurately at high speeds (e.g. 16th notes @ 120bpm).

The detailed explanation

The DMX protocol allows for updating your lights at a maximum of 40Hz – that’s one update every 25ms. However, because many lights struggle to cope with the 40Hz rate, some controllers (including DMXIS) deliberately throttle the update rate to 25Hz, or one update every 40ms. This means you will run into timing anomalies quite easily if you try to program fast strobes.

A little math is required to explain further. Say you want your lights to flash on every beat of a 120bpm song. Each beat lasts 60/120 = 500ms, so to flash the lights on/off requires a DMX event sent every 250ms. This is much higher than the 40ms update rate, so all looks good…

Now, say you want to flash on every 1/2 beat. This needs a DMX event every 250/2 = 125ms. This is higher than the 40ms update rate, so every update will be received by your lights. But, you will start to notice some timing inaccuracies in the strobe effect…

Now, let’s go to 1/8 beat strobing. This needs a DMX event every 62.5/2 = 31.25ms. So now we’re in trouble – not only will the lights be unable to accurately track your desired pattern, but you will actually drop some events because the DMX hardware simply cannot keep up with the changes…

Unfortunately, the DMX protocol simply doesn’t handle fast changes well. If you want to strobe quickly, use the “strobe” macro feature that is built into most DMX lights. While they may not strobe perfectly in sync, they will at least strobe at a consistent rate.