CX Programmer CPH1 AD/DA Settings

Hi Everybody,

I would like some of your opinions on a scenario I have run across:

I have a CPH1 OMRON PLC, I have a 4-20 mA input signal (Dew Point Sensor).
I have it scaled so that 4 mA = -148F and 20 mA = 68F.
These modules have 4 input channels with a dip switch that puts an external impedance of 250 Ohms when the dip switch is on.
On for current signals and off for voltage signals.

So in the CX Programmer under the settings their is a tab that reads
"Built in AD/DA" depending on your channel you can select the various signals.

This was selected as a 1-5 volt signal on the channel, the dip switch was on, and it was getting a 4-20 mA signal. What do you guys think this small error would do to my output readings? What are the consequences of selecting the wrong signal to read?

Thanks,
Buddader

1-5 volts and 4-20ma are essentially the same signal so there should be no effect at all.

(4 - 20 mA)x 250 Ohm = 1 - 5 V.

I get that they are the same range, but I have found an error when you change the settings in the PLC program, download, and reset power. When I switched the "Built in AD/DA" settings to a 4-20 mA it started giving me the correct reference number. The latter setting was reading 15-20 F off? I am curious why this error has occurred.