MicroLogix 1100 analog

[Dorrance]

I just have a quick question on this processor. I am making a project with 18 analog inputs so I bought 4 - 1762-IF4 expansion cards and the plc already has 2. My question is, when I hook up to the ML 1100 analog input and open the inputs section on RS500 and change from bits to decimal I get a voltage reading from 0 to 10V or that’s what it seems I had 650mV coming in and the input read 65?
On the expansion card I ran the same input and changed bit to decimal and I got something like 40000. I’m not real accurate on my numbers but am just asking about the difference. Just wondering if anyone knows why it shows 2 ways.
This isn’t very important because I can work with both values, I’m just curious why?

 

[Mickey]

The values you see in the input word depends on how you have the card
setup/configured.

Voltage/current (set by dip switch).

Raw data format set by software (RSLogix500)card's configuration.

Raw/Proportional or Scaled for PID

See pdf link

http://yoingenieria.com/wp-content/uploads/2015/10/1762-IF4.pdf

 

[Bullzi]

Thanks Mickey,
I was looking for that info to give out and couldn't find it. The Installation manual for the IF4 doesn't give the D/A count info. Kind of important in my opinion

The on board 0-10V analog input uses 0-1023 for its scaling. So it would make some sense that if you put an imaginary decimal in the second position it would be very close to your actual voltage.

 

[Firejo]

The analog inputs on the MicroLogix 1100 are voltage only (0-10VDC) but the analog inputs on the 1762-IF4’s can be either current or voltage. The IF4’s voltage range is -10 to 10 VDC and the current range is 4-20mA. If I had to guess (and that’s all I can do) I’d say that the 1762-IF4’s are set to current. However even if they are set to voltage I’m guessing (again) that they will show different values than the onboard analog inputs because they the span is twice as wide but the words that represent them aren’t. I don’t have any “hands on” with the IF4’s so I can’t say any of this for sure but I’ll bet someone else out there (Ken) would know off the top of his/her’s head (Ken).
P.S. Written but not posted before the other two posts