Connect signal to PLC and DeltaV???

Hi there!

I was wondering if anyone out there could tell me if it is possible to connect a 24V signal (from a sensor) to both a PLC (Siemens 1200) and a DeltaV controller simultaneously? I'm not talking about using Profibus communication or protocols of any kind, just literally connecting the same signal to the digital inputs of both controllers.

Thanks.

I haven't seen that in practice. If both are sourcing, or both are sinking, and if both are using the same DC supply, and you don't have issues will pull-up or pull-down resistors it could work. Do you have the option of one receiving the input and sending the signal to the other ?

Since this is a descrete signal it should be possible to run the two in parallel. This isn't any different than using one signal to light a pilot light and turn on a PLC input. Just make sure your polarities are right, and that you have a return path for the - side.

Hey thanks for your replies. I thought that it might work, it seems pretty simple after all. My only concern was that this signal may somehow connect the two incompatible systems.

I doubt it will work, Delta-V has sinking digital inputs, the absence of voltage is a logical 1, most other systems are the reverse. I know Mitsubishi PLC's used to work this way too, but I have not used them in many years. An interposing relay with two output contacts might be required.