Micrologix 1500 Analog Input Help

[Quietman 0]

All, I've gotten about halfway through the messages in the board, and will continue looking for an answer, but thought I'd post all the same. It's been about 10 years since my A/B programming course, and 8 since I've actually programmed. I've set up my Micrologix 1500 with 3 additional modules, my analog module (1769-IF4) in the last position. I've used the I/O configurator in RS Logix 500 to set the INPUT RANGE to +/-10VDC and the DATA FORMAT to Engineering Units. Now, my question is HOW to read the analog I/O? I'm thinking I have to: A) Use a BCD type command (i.e. FRD from I:3/0) to move the data from the I/O point into an integer data file (N:7/0 for example) B) Then exploit the value in the N7 register each scan? Does this sound about right? Many thanks in advance for any help. Roger

[mgvol 0]

No, you read it straight in from the raw address (i.e. I:3.0). Notice that it is I:3.0, not I:3/0; this denotes that it is using the whole word since it is analog. Then your other channels would be I:3.1, I:3.2, I:3.3. If your Micro is a Firmware series C 7 or greater you can use the Scale-With Parameters (SCP) instruction to scale into engineering units and move them into an integer or floating-point file.

[Quietman 0]

Thank you very much! I apprecaite the response and information. Roger