Posted 6 Jul 2020 (edited) Hello all, Thanks for the forum which has provided me with a lot of help overtime. I'm posting my first thread since I can't seem to find an answer to my issue. I'll quickly explain the situation: I'll be installing a RTD sensor to a GE Fanuc IC200ALG264 analog input module using a 4-20mA converter. Everything is fine except I can't seem to understand the polarities of the Fanuc inputs. I'll explain better: the module has an IC200CHS022 for the terminals, 15 terminals total, and the manual is reporting a "number" and a "connection" for each terminal. Now, the "number" seems to correspond to the visible pin of the terminal. But the positive and negative symbols are represented on the "connection", which I can't seem to wrap my head around what it means. Attached are abstracts from the manual and a photo of the terminals. Please tell me where to connect positive and negative outputs of the 4-20mA converter. Thank you. Terminals Table Terminals drawing Terminals photo (front) Edited 6 Jul 2020 by lupodellasleppa 1 person likes this Share this post Link to post Share on other sites
Posted 11 Jul 2020 One key word under product description is 'single ended'. That means the (-) side of all the signals are connected all together at one point. The terminal labeled RTN on the Field Wiring Terminals table means return, or the common, (-) side of the input(s). The wiring diagram shows the field device on the left with its positive output connecteed to In, (-) connected to RTN. The In (I2, I4) number represents the current source field device (I is current in Ohms Law). What is not spelled out is what happens when the field device is a loop power transmitter and needs a loop power supply. So the (+) side of the current signal goes to the An terminal, which is either - the negative terminal on a loop powered transmitter (because the positive terminal of the transmitter is connected to the Power supply (+), or - the positive output from a 3 wire or 4 wire field device. and then either - the negative (return) of the loop power supply output connects to the RTN terminal - the negative outputs from either 3-wire or 4-wire field devices are run to terminal blocks, jumpered together and then connected to RTN. The wiring diagram essentially shows the same thing - Test it with a single field device. I haven't a clue what all the Bn connectors do. Shame they can't be used as RTN or (-) connections. Share this post Link to post Share on other sites