Question:  Can I wire up a Sony NiPROS DS-560 camera CCU to a Clear-Com party-line system via the 3-pin XLR connector?  Will it support multiple CCUs in this configuration?
Answer:  One DS-560 camera CCU can be wired directly to a Clear-Com party-line system using 3-pin XLR cable.  The party-line system can typically support one camera CCU in this configuration due to the camera impedance on on the party-line channel.  Adding more than one CCU in this configuration will load down the PL audio down making the PL audio low and unusable. 
Clear-Com always recommends that when connecting camera CCU's from any manufacturer to our Partyline system. The best solution is to set the camera CCU into 4wire mode and convert from 4wire to 2wire using our IF4W4 interface unit (http://www.clearcom.com/product/partyline/interfaces/if4w4) 

See below the diagram for connecting ONE camera CCU to the PL main station.