Pressure Transducer

I've never done this so any help would be greatly appreciated! I want to use a 4-20mA pressure transducer to measure the pressure of a hydraulic cylinder on a press type machine. The min and max pressures are 250 - 1000 psi. I'm using a micrologix 1500 controller and have a 1769-IA16 Analog input module already interfaced to the PLC. Is there someway to interface the 4-20mA output of the transducer to the input of the card? Would i need a seperate DC power supply for the transducer?

Thanks!
Brian

You will need to check the power consumption of the transducer + the 1500 versus the output of the power supply. I have done it in a pinch, but it is a little cheesy.

If I got that all setup, would the rest just be a matter of connecting the transducer to the module and scaling the current to the pressure?

I'm using a micrologix 1500 controller and have a 1769-IA16 Analog input module

Click to expand...

Think you'll need a 1769-IF4 for the ML1500..... I think the IA16 is a 120VAC input module.

The rest is pretty straight forward. Use the SCP (Scale with Parameters) instruction to set your limits ie 250 psi=4mA - 1000psi=20mA.

Don't see loading an issue if thats all your driving......

Also, I suggest that you read Ron's gripping epic novel on the subject that can be found right here:
http://www.plctalk.net/qanda/showthread.php?t=15069&highlight=scale

The 1769-IA16 is indeed a 120 VAC discrete input module. You will get some interesting, but not good, results.

The manual for the analog input card shows the electrical connections required. Make sure you read it well.