Motor Valve control with Siemens Logo?

Hey

Anyone who have managed to construct a motor valve control with Siemens logo and is willing to share?

What I mean is software controlling a motor valve depending on the outdoor and backtemperature in a building for example.

Kind regards
David Andersson

I think the Logo is the same as the Moeller easy relay and the AB Pico. If so, we use them all the time to control the level of tanks with a 4-20 MA input.


Most of these programmable relays are limited. Unless you get to the top line models (and why would you when you can get so much more with a PLC)you have a couple of analog iput (0-10VDC) and the rest digital. You usually don't have any analog output. Will your valve be proportional or OFF /ON?

If it's off / on, you can read the 4-20 by bridging a 500 ohm resister in the loop and reading a 2-10VDC input at the smart relay. You can then turn the valve off and on as required. If the Logo is not like the Moeller smart relay or your valve is proportional, sorry for wasting your time reading this information.

I'm not sure of the correct english term for my kind of valve. It might be a bypass valve, or a bypass flow valve.

/David