Negative Current - Analog Output

[JaydonElcock]

I am troubleshooting an actuator which is not responding to the plc code. The range in the channel of the Allen Bradley 1756-OF8 Analog card is set to 0-20 mA. The range is set from 4mA (1638 engineering units) to 20mA (8191 engineering units). When I signal to 1638(4mA), I get a reading of 2mA. I then set it to 8191(20mA) and got a reading of -2.5mA. Then I set the value to 0 engineering units which is outside of the range and I got a reading of 4mA. Does anyone know where I should go from here?

 

[GaryS]

YaydonElcock Welcome

I just set the module in a test program
And the way to set that up is Rang 0 Ma-20 Ma as you have done
But scaling :
The default engineering units as percentage
High Signal would be 20.00 Ma = 100.000%
Low Signal would be 4.00 Ma = 0.0 %
That should give you what you want
You need to set each channel separately
I found no provision to do other engineering units