Controllogix Analog Input Module 1756-IF16 - Signal Level?

Is there a way to see what the actual field signal value is going into each channel of the Analog Input I/O card 1756-IF16?

In other words, I want to know what the current signal level from the field device is ( Ex. Is it 10mA, 15mA etc..).

I was hoping that when we go online with the controller using RSLogix5000, if we drill down to the card, and channel of interest, there would be some information under the Module Properties window regarding the actual field signal value currently being read in.

If the input is configured for engineering units, 4ma will be represented as 4000 in the tag, and 20ma will be represented as 20000. Otherwise you will have to scale the tag to find the actual mA.

rupej,

Yes the input is currently scaled to Engineering Units.
However, I have worked with Distributed Control Systems in the past where for each Analog I/O channel input, there is the ability to see both the Engineering value AND the field signal ( Ex. 4 - 20mA) side by side. It does not appear that this possible with Controllogix I/O cards or RSLogix5000 without scaling the tag's engineering value?

Jjimene03: I do not think so, at least I've never seen that both readings can be seen at the same time without scaling one into another.

jjimen03 said:

Is there a way to see what the actual field signal value is going into each channel of the Analog Input I/O card 1756-IF16?

Click to expand...

Usually, you can configure each canal in 1756-IF16 using engineering units. Suppose you have a PIT with range from 10 to 250 psi, then you configure the channel as:

4mA --> 10
20mA --> 250

Drilling down to the channel data, you'll find a value between 10 and 250 units.

If you need both values (raw and scaled), I think you have 2 options:

a) Keep the engineering units in the module's channel and use a SCL instruction to recreate the raw value (mA).

b) Configure the channel this way:

4mA --> 4
20mA --> 20

And use a SCL to get the scaled value.