Posted 6 Feb 2019 Hello everyone! I am having some issues with the internal wiring/wiring of the 1756-OF8 analog output card in my Controllogix L55 controller. I have just recently started using Allen bradley products, so please bear with me. If my memory serves me correctly, in my past experiences with other plc vendors I thought I was required to provide 24vdc+ from the power supply, which is common to all the channels used for driving the analog out(4-20ma) to the field device being controlled. But I can find any documentation from Allen Bradley that supports this. Can anyone shed some light on how to connect the power supply to the OF-8 card. Thank you!! Shane Share this post Link to post Share on other sites
Posted 6 Feb 2019 Looking at the wiring diagram in the user manual, the 1756-OF8 doesn't require an external power supply connection. The analog signals are generated within the module using power it gets from the backplane. See page 144 of this manual: https://literature.rockwellautomation.com/idc/groups/literature/documents/um/1756-um009_-en-p.pdf Share this post Link to post Share on other sites
Posted 6 Feb 2019 Joe, Thank you for the speedy response! Share this post Link to post Share on other sites