Pfeiffer TC600 Turbo Pump Driver Notes
The TC600 Turbo pump takes a 24V input. The remote interface also uses 24V signaling. However, this is not derived from the 24V input.
Rather the TC600 seems to use a N channel transistor in combination with a UC3845, transformer and capacitor (marked 1 in the diagram below) to create an isolated AC supply which is then rectified (somewhere) and then regulated down to 24v by the marked LM317:
Digikey CSV With almost all parts required for lower board (aside from resistors, some transistors)