We use controllogix analog output 1756-OF8 (8 channel). We use 4-20mA as speed ref to four units of AB 1336 drive. The analog output only have one signal common-RTN (pin 5, 6, 15, 16). Could we use one common to all 1336 drive? any idea?
Thank you
Tony

I would reccomend running an individual common from the module to each of your drives. If I understand your question, you would like to daisy chain the commons between your drives instead of running one common for each, this may or may not cause noise problems, in any case I don't think it's worth the risk. Wire is cheap....

JJ

Thank you for reply.
I mean that in controllogix analog output only have one common. All returns are tied together internally (on inside module). This mean that the module only have one common (like single ended connection not isolated). I want to connect this 4-20mA output as speed ref to multiple drive (four units).
Could I daisy chain all the return signal of drive (for AB 1336 drive, signal common is on TB-2 terminal #4)?