KN (Customer) asked a question.
I have a Click C0-02DR-D that I am trying to use with a linear position sensor (LRSI-18-025-A-00-20-A), 4-20mA. However, I am not able to get an analog signal via the input AD1I. Has anyone had this issue or similar?
Hi KN,
http://alliancesensors.com/sites/default/files/pdfs/LRS-18_Datasheet_v2.3.pdf
The first thing that I would do is double-check your wiring. It looks to be similar to a three-wire device like the following diagram.
Thanks,
Garry
https://accautomation.ca/series/click-plc/
Yes, it is 3-wire and similar to that on your drawing. I have 24V going to the RED wire on the sensor, 0V going to the BLACK wire on the sensor, and the green wire from the sensor going to AD1I. I also have 0V going to ACOM.
Hi KN,
Have you wired in a multimeter in series to measure the 4-20mA signal?
Regards,
Garry
I have, and it shows the same as the input via the click software - a non-changing 6 or 7 mA, depending on if the sensor is fully extended or not. I have also removed the green input wire from the PLC and gone through the meter to 0V, and it works just fine - 4 to 20mA through the range of the sensor stroke.
Have you connected the 24VDC supply to the analog input card? This should be the same supply as the sensor.
Regards,
Garry
Have you tried AD2i? If the sensor works with your multimeter but not with the CLICK, then the CLICK seem like the most likely suspect. I think ideally one would try another CLICK entirely, but trying the other channel might tell you something.
" and gone through the meter to 0V, and it works just fine"
You are sure that is the same 0V as is connected to ACOM right?
I really can't understand how your meter and the CLICK could agree on the same wrong value while the sensor works correctly with the meter alone. I could imagine, for example, the 200 ohm input load resistor in the CLICK being broken or missing, but in that case the CLICK would see maximum value (sensor would output maximum voltage trying to shove current through the high impedance ADC) but the meter would show virtually noting (since, if the resistor is open, negligible current flows into the high impedance ADC)
Yes, AD2I has the same issue. This is the second Click PLC I've tried (I though the same and sent the first one back for a replacement). I only have one power supply in the circuit, so the 0V is the same throughout.
Also, I have verified the 100-ohm resistor between AD2I and ACOM as well as AD1I and ACOM. This issue is very confusing. I wonder if the sensor does not have enough power to drive the input, but then again it works with an external 250-ohm resistor and AD1V to give me 1 to 5V...
Have you configured the input for current input?
I think that the default is 0-5V