With a PLC is it possible to get analog outputs of 0-30VDC @ 1.0 Amp max? It looks like the PLC analogs outputs go from +/- 10VDC. Does anyone know of a way to get a variable controlled analog from a PLC (possibly through another device) to get this kind of control.

There are many devices that do that. A DC amplifier, for instance. But they usually are quite expensive, need a power supply and also (usually) have bipolar outputs. I think that you should look for a "programmable" power supply. 30 V and 1 A is kind of a standard specification. You get all you need in one packet. Connect to mains. Input your 0 - 10 V to the "programming" input and connect output to your load. Done!

I thought I would give an update to my solution, as it is now installed and running, for some time now. (delays by others, as usual!!!).

I bought a Instek GPS-S table top power supply that could supply 0-30VDC @ 3Amps. The key to it was that it had a slave mode, which could accept a Analog input of 0-10VDC, that would inversely give an output of 0-30VDC. The analog input was only required to be in the milliamp range, thus not over-loading the Allen-Bradley PLC analog output.

The power supply was in the $175 dollar range.

So the PLC Analog Output is stepped from 10Volts to 0 Volts, with approx. 2 seconds between steps. I can now see what nominal voltage the valve coil picks up at. Then once this is established I vary the PLC output from this nominal voltage back towards zero and record what nominal voltage the valve(Safety valves) coil drops out at.

MORE NEWS