Correct me if I'm wrong but if you are currently using your PCM1001 with the adapter cable for the L1840, I think it is just a regular mains cord that plugs into the TIMER input on the EST1000 or EST2000 color head to bypass the L1840's built-in timer.
With just about any other enlarger (that does not have it's own built-in timer) the PCM1001 will be the enlarger's timer.
Other than timing the exposure, I don't think the PCM1001 can control any other aspect of the enlarger or color head.