1762OF4 Analog Output

What are raw values for a 1762-OF4 Analog Output card?

You can configure these modules for "Raw/Proportional" or for "Scaled for PID".

In "Raw/Proportional" mode the full scale output is a 16-bit signed integer, so +32767 counts = Full Scale Output.

The "Scaled for PID" means that they are scaled to take the full scale output of an SLC/MicroLogix PID instruction, which is 16383 for Full Scale Output.

Here's the tricky part, which is why there are a couple of Knowledgebase documents about it (38470 and 34193):

Full Scale is 10.5 volts (in Voltage mode) or 21 mA (in Current mode).

So even though the module is nominally a "0-10V DC" module, the full scale output value will actually generate 10.5 volts.

If you take into account the extra half-volt or extra milliampere, you'll get your best results.

The excerpt from the Knowledgebase that I always write down when I'm using these modules:

Code:

Raw/Proportional

Data Table Value   Voltage/Current Value

    32767                10.5 Volts
    31206                10   Volts
    0                     0   Volts

    32767                21 mA
    31206                20 mA
    6241                  4 mA
    0                     0 mA

Click to expand...

Thanks Ken.
I'm using the Raw/Proportional and 4-20MA.
I'm not getting the correct mA from the card.
0 - 0% - 0mA
8191 - 25% - 5.2mA
16838 - 50% - 10.5mA
24575 - 75% - 15mA
32767 - 100% - 20mA

And here is the scaled for PID.

I always use 6240 to 31200 for 4-20, raw / proportional that is.

Terrep said:

Thanks Ken.
I'm using the Raw/Proportional and 4-20MA.
I'm not getting the correct mA from the card.
0 - 0% - 0mA
8191 - 25% - 5.2mA
16838 - 50% - 10.5mA
24575 - 75% - 15mA
32767 - 100% - 20mA

Click to expand...

See chart below

Remember 0 counts (raw data) = 0ma 0%
32767 counts (raw data) = 21ma 100%

If you are looking for % of 4-20ma then see chart 2

6242 counts (raw data) = 4ma 0% 0f 4-20ma

31206 counts (raw data) =20ma 100% of 4-20ma

Does the 1762-OF4 card require a Position Feedback to operate?
The reason I'm asking, I having a issue moving a actuated valve with this output card but I can move the valve with a 789 process meter.
If I source the valve and give it 12mA the valve will move half way.
So I thought it may be in the wiring of the PLC card.

Thanks again for your help

It may be in the wiring to the card. After a quick look at the manual for that card it looks like you have to make sure you are connecting to an amperage output and not a voltage output.

Bubba.