AB 1746-NIO4V ANALOG MODULE

HI PLC GUYS

I HAVE SOME QUESTIONS FOR THOSE WHO ARE FAMILIAR WITH ANALOG MODULE 1746-NIO4V:

1 WHAT IS THE PURPOSE OF THE TERMINALS 6 AND 9 ON THE OUTPUT OF CHANNEL 0 AND 1 IF THEY ARE NOT USED WHY THERE.

2 WHEN ANALOG COM TERMINAL USED OR NOT USED.

3 ONE OF THE OUTPUT ON THIS MODULE IS CONNECTED TO A 50 MILI VOLT FULL SCALE DEFLECTION METER FOR ARMATURE CURRENT WHICH A POT (I CAN NOT REMEMBER THE OHMIC VALUE FOR NOW)IS CONNECTED IN PARALLEL WITH THE METER WHAT IS THE PURPOSE OF THIS POT AND ITS IMPORTANCE.

I HAVE SOME OTHER QUESTION RELATING TO THIS TOPIC WHICH I WILL POST IT NEXT WEEK.

THANKS

1747-RTFM

If you don't already have it, look online for the user manual for the 1746-NI04V. It will help.

http://www.ab.com/manuals/io/1746/174664.pdf

Page 3-13 has a particularly helpful wiring diagram.

1. Several different A-B analog input modules use the same 12-position connector. If the card was an all-input module instead of a combination module, Terminal 6 and Terminal 9 would be differential input terminals. These terminals are skipped on the output section of the NIO4V (instead of using a smaller connector or putting unused terminals on the end) just to make the spacing of the Analog Common terminals consistent down the terminal strip.

2. The Analog Common terminals are internally connected on the module. When you're using single-ended Inputs (as shown on page 3-15), all of the input points are relative to the Analog Common, rather than relative to individual commons (labeled In 0-, In 1-, In 2-, In 3-).

3. There is a note on page 3-8 that says the load on an output of the NIO4V must be 1K ohms or greater. The potentiometer may be there to provide extra loading to the output. I'm not familiar with applying potentiometers to trim voltmeters.... hopefully someone will post their experience with such things.

I recall from a post you made in the past that your PC resources are a little limited... get in touch with your local A-B distributor for a free copy of that manual if you don't have the time or bandwidth to get it online.