MLR (Customer) asked a question.
Load Cell to Click Plus PLC
I'm planning to connect four load cells to a Click PLC using the C2-01CPU and a C0-04AD-2 analog input module. Each load cell outputs 0–2 mV, and I understand that I'll need to convert this to a 0–10 V signal to be read by the analog input card.
I’ve been looking at signal conditioners, but most of what I find are designed for 0–5 V input to 0–10 V output, which doesn’t match the millivolt-level signals from my load cells. These conditioners also don’t seem to allow for scaling.
Can someone advise on the best way to convert the 0–2 mV output from each load cell to 0–10 V? Or suggest a better, more cost-effective approach?
Thanks in advance!
The signal converter will supply the correct excitation voltage to the load cell. The 2mv specification of the load cell is actually 2mv/v or two millivolts per volt of the excitation voltage at full load. The convertor will properly amplify the low level balanced signal from the load cell to the appropriate voltage for the PLC inputs. It will be ok. Just follow the wiring diagrams for the signal conditioner and the PLC input cards.
That makes sense now. Thank you
Last Century, I did a Load Cell Input to a PC 286.. I had to use a Display Unit that would do the Conversion for me, then it did a Continuous Text Data output that I did a File Read on.. Resolution was 5 Lbs in 20K Lbs
2mV/V is the spec of the bridge in the load cell. If you want fine resolution, get a proper load cell amplifier with 0-10 or 4-20 output. Many will have serial or ethernet comms to maintain resolution as something like a 12bit input on a click does not give you much to work with.
Do you know of a cost-effective amplifier with Ethernet communication and 0-10? I am looking through AD, and it doesn't look like they have anything.
I dk if they sell any. Laumas is cost effective.
Automation Direct just released today that they are now a Laumas vendor.
You could use the LS Electric XEL-BSSRT Bus Coupler for Modbus TCP or EtherNet/IP. Then connect two XBF-LD02S load cell modules to it. That would give you 4 load cell inputs.
I'll consider that. Thanks.
The Laumas TLE or TLB4 which just launched might be a good option for you. They accept load cell input and can output an analog signal or can be accessed via RS-485 Modbus.
https://www.automationdirect.com/adc/shopping/catalog/process_control_-a-_measurement/weight_-z-_force_sensors_-a-_electronics/controllers_-a-_electronics