I have an application that requires load cells to weigh a liquid. It has been many years since I had to do this. What is the best way to an AB PLC. Millivolt card or load cell with 4-20ma out. Who do you recommend as a supplier of load cell hardware. Thanks

Hardy Instruments XXXX-WS

For ControlLogix - 1756-WS
For CompactLogix - 1769-WS
For SLC - 1746-WS

http://www.hardyinstruments.com/process_we...lug-in+modules/

Fantastic modules, if a bit pricey.

If you want to go pure millivolt, there are lots of options. Any appropriate thermocouple card for instance.

We always use the load cell with 4-20mA output, so that we can third party certification. I recommend Rice-Lake or Metler-Toledo. MT has remote I/O options for most AB platforms if you want to go that route.

There are also load cell signal conditioners. I've used Action Instruments WV448s. These convert load cell to 0-10VDC or 4-20mA. The only thing with these is that you'll have to calibrate the analog signal to the weight.

The Hardy modules that rdrast mentioned are great! As are the MTs that Ken mentioned -- especially if you get one of the comm options (CNet, DNet, ENet, RIO, DH+, Profibus).

All great suggestions.

We also use a BLH DXP40 Load Cell Amplifier which speaks AB RIO as either 1/4, 1/2 or full rack and can support 1 to 4 load cells. Unit includes Cal and Tare functions.

Thanks for the input.

If you have device-net or ethernet/IP IO, or are not averse to adding it, then I recommend using a Beckhoff KL3356 module. ~$180 US

http://www.beckhoff.com/english.asp?bus_terminal/kl3356.htm