Looking for a PWM for PVEH

Hello everyone. I need to control a PVEH valve with a CompactLogix PLC. I have difficulty finding a 4-20mA to PWM to actuate the valve. do you have any suggestion?

Sounds like what you want is a 1k ohm resistor?

That’ll make 4-20 volts, danfoss @24v takes 6-18 volts control signal.

1 watt resistor is fine.

Thanks for your reply. This is my first time working with Danfoss solenoid. My understanding is the PVEH takes PWM signals. So, I need a module that convert the 4-20mA to a pulse output. The PWM module should change the duty cycle of the output pulse according to the input current.

The danfoss actuator can take a PWM input (greater than 1khz) but it prefers an analog voltage input. The resistor will provide an analog voltage. The PVE manual has some great explanations.

I don’t know what kind of output cards you have but many are selectable between 4-20mA and 0-10v analog voltage output. They basically have a resistor built in. Can you use 0-10v output mode and then power the valve from 12v?

What output card are you using?

The output card is 1794-OE12. I fouud a PWM module. The max frequecny of the module is 999Hz. The PVEH manual says it is recommended to be >1000. Hopefully it works. Thank you so much for your reply!

That card is configurable for 0-10v output by simple setting the setup bits correctly. Its covered in the card manual.

You can turn your 4-20mA signal into an analog voltage with a $1 resistor.

Either of those options are basically free, reliable, and have 0 lead time and can be working in the next 10 minutes, I’m sure you have a resistor somewhere in the shop.

I don’t understand why you are focused on using a module, but it’s up to you :-p

Yes frequency must be higher than 1000 Hz so the pveh think it is a steady analog voltage.
Somewhere in the Danfoss papers they have a simple setup where they control the valve with a potentiometer.