Identifying a Legacy Unison Processor

Finding the Label

Unison processors all look more or less the same, but they're differentiated by a label on the right-hand side that says "Unison architectural control module." In order to view this label, you will need to to open the rack door. If your processor is in an equipment rack instead of a dimmer rack, there may be a lack faceplate over it that also needs to be removed.

Identifying the Processor

If your processor is in a dimmer rack, it will have a label that looks like this:

If it is in an equipment rack, the label will look like this:

In either case, one of the black diamonds on the sticker will be filled in. The 3- or 4-letter code to the right of the filled diamond identifies the type of processor you have.