rslogix 500/1746 no4i /pv600

[michaelplc]

I am having trouble getting an output from a no4i module using a 5/03 processor. I am writing an integer value into the panelview 600 at n:11.0 then checking it for proper limits in the rslogix 500 progam, move it into an scp function with the output at the analog output module. I have a 250 ohm resistor to check the output but the output is not varying.

 

[Allen Nelson]

Please post your SCP logic.

A few things to check:

• Is the PLC in Run mode? (stupid question, I know, but the old tech support "Is it plugged in" line solved about 10% of the calls)
• Is the SCP instruction in a subroutine, and if so, is there a JSR to that subrouting (a variation of the first question).
• When online, look at the the output register (O: ). Is the value at the point you are trying to measure between 6242 and 31208 ?

 

[rogerhollingsworth]

Is your INPUT varying?
Does the corect data appear in the PLC data table?
Did you place a meter at the output module parallel with the resistor, reading voltage?
Did you place a meter at the output module in series with the resistor reading amps?

Double check your module dip swith settings, is S1 selected external or backplane, does that selection match your scheme?

The data that isn't changing, is it at the above range or below range settings?
Does your module have 24vdc power?

Just thumping the bushes to see what falls out.
Roger

Publication 1746-6.4 will get you in good shape.

 

[michaelplc]

Hope eveyone had a good holiday and will have a happy new year.
Sorry I haven't posted a reply, but I have been trying to meet deadlines.
1. Yes, I did measure voltage and current with a 250 ohm resistor
at the output.
2. Yes, I did have user's manual.
3. I used a TND instruction on the first rung and input integer
values to outputs.
The end result was that I used different integer addresses to move the values into the output and I had a cable that was wired wrong
going to the input for output device, which is a current to pressure
controller. Solved the problem through perseverance.