This is an article that discusses some technical issues relating to Burien Little Theatre’s light board to an interesting light filter device. Most theatre fans will find this to be of no interest at all.
The issue is addressing the PanCommand Systems, Inc. CF-300 Color Fader to an ETC Express 48/96 light controller board via DMX cable. Those interested in this issue can click on the “continue reading” link below to continue reading.
The BLT light board is an ETC Express 48/96 controller. As the model name implies, it can be used as either a dual 48 channel controller with preset, or as a 96-channel controller. For BLT, the latter is the usual setup. Even though we have only 48 dimmable light circuits, we often use the “lower 48” to control other fixtures and devices via the board’s DMX bus.
One of the devices that lighting designer Dave Baldwin wants to use in BLT’s new production of Frankenstein is the PanCommand Systems, Inc. CF-300 Color Fader. This device can be used to dynamically change the color of a light it is attached to, rather like a barn door, to a lighting instrument. This particular model uses cyan, magenta, and yellow (CMY) filters of various intensities to modify the color of the light streaming through it.
Since this was the first time using this device at BLT, it seems worth a bit of time to explain a simple way of connecting it to the light board.
First, if the light board has been patched in any in a previous production, it makes sense to reset the light board to the default patch. This can either be done using the “Clear Show” or “Reset Patch” settings. Otherwise, in all likelihood, the correspondence between the board’s channel numbers and the Color Fader’s group and address settings will not be as it’s described later in this article.
The next thing to do is connect one of the Color Fader power supplies to the board’s DMX #1 bus, using one of the five-pin DIN cables. This can either be done by daisy chaining it with a device already on that bus, or by plugging it directly into the back of the board, like so:
Image credit: All photos by Craig Orsinger/Burien Little Theatre
Using the four-pin DIN cables, up to six individual CF-300s can be connected to the CF power supply.
With the power supply and the board set up, it’s time to try setting up a CF-300.
Addressing the CF-300s
The CF-300 Color Faders are addressed by unique combinations of Groups and Addresses. There are 99 possible Groups, and each group has twelve Addresses. I’m using capital letters here to signify the CF-300’s addressing scheme, rather than to discuss the concepts generally.
As the photo at left illustrates, the CF-300 is addressed using three wheels. Two assign the Color Fader’s Group number, and the rightmost assigns the Address. The wheel on the left is the most significant digit. The CF-300 shown in the photo has an address of Group 07, Address 1. That corresponds to light board channel 73. This Color Fader’s yellow filter would be controlled by channel 73, its magenta filter by channel 74, and its cyan filter by channel 75.
If the ETC board is in its default patch configuration, channels are assigned one per CF-300 address. Groups are numbered 1 thru 99, but only the first eight are addressable by default on the BLT light board. Since each Group is twelve addresses, the channels line up this way:
|CF-300 Group||CF-300 Address||ETC channel|
and so on. Of course, given how the CF-300 addressing scheme works, it is possible to put a Color Fader’s three addresses at any arbitrary set of three consecutive channels within that range of channels. For instance, if another device were already set up on channel 13, the first Address that is used in Group 02 would be 2, and the Yellow channel for that box on the ETC board would be 14. The table, however, represents the simplest configuration, and assumes none of the light board channels are already in use.
In practice at BLT, since the first 48 channels are normally used for dimmable light circuits, the first channel that is likely to be assigned to such a use is channel 49. This corresponds to CF Group 05, Address 1.
This table shows the ETC board channels that correspond to each group.
|CF-300 Group||ETC Light Board Channels|
Nonstandard patching schemes and other changes from the default configuration will no doubt make this solution invalid. It may also be possible that other DMX addresses can be assigned particular light board channels. Still, this is a simple solution that requires relatively little improvisation and provides a straightforward set of channel assignments.