I am having an issue with a MirPro 4-20 ma input.
When the device receives a 4 milliamp signal it displays properly however as the signal increases it does not scale appropriately to the point where a full 20 milliamp signal only registers as about 5.5 both being displayed in the config and received on the other side. It is proportional but not scaled properly. Calibrating the device moves the under scaled range to match the present input not stretching the scale out. (ie: calibrating at 20 milliamp changes the range to appx 18.5 at 4 MA to 20 at 20 MA.)
Is there a way to scale the transmitted number to match the given input or is that something that needs to be returned to be fixed?
That is strange. I do not believe I have seen that before. Typically I calibrate the input unit by applying 12mA to it and calibrating at that level, then it is accurate from 4 all the way to 20. Are you looking at the web interface for the 4-20mA input unit when calibrating? Have you tried calibrating at 12mA?
Thank you,
Travis Elliott
Yes, I have tried calibrating all through the 4-20 range but it has only shifted the range to match at the calibrated point but still scaled incorrectly.
20 ma applied:
12 ma applied:
4 ma applied:
Yeah, it sounds like the input is damaged as best I can tell.
I would recommend sending the units in for RMA which you can do by completing the form here:
https://ncd.io/contact-us/product-returns/
Thank you,
Travis Elliott
Hi,
Your RMA is at my desk for testing.
From this thread I can see the issue seems to have been with the MirPro 4-20mA input unit.
I applied a 12mA active signal to the input and calibrated at that point. I then generated a 4 mA signal and the input reads 4.0 mA. I generated a 20mA signal on the input and got the expected 20mA reading on the input.
I do not see anything wrong with the input unit.
Is there any additional testing you would like performed prior to return? Would you like to provide more information about the signal you are attempting to apply to the input? Perhaps it was just improper wiring.
Thank you,
Travis Elliott
Good Morning Travis, thanks for your help. I can’t explain your results compared to ours, but if it works, it works. If you wouldn’t mind ensuring that input gets translated to an equal output signal on the other end on the receiver, we would be grateful. We’ve used another one of these 4-20 system at a local state park for transmitting water levels and it works great, the one you have is intended to be a back-up in case a future problem arises with the one that’s in the system.
Thanks,
Tim
Good Afternoon Travis, just checking in. Have you had a chance to verify the operation of the two units (in-out) working as a pair?
