VC <=> PLC signals update rates

Good afternoon,

What is achivable I/O signals update time when considering communication between VC and PLC (let’s say Siemens CPU 1500 series).
What are the options to connect Siemens PLCs to VC ? Of course OPC UA is always an option, but I don’t expect this technology to be very responsive.

Let’s say I have a device with a sensor (encoder for example) whose signal is triggered only for duration of 30ms. Will PLC even notice this signal arised ? We assume that PLC’s control loop is very fast ( 5 ms ).

Kind Regards

The communication itself can probably achieve e.g. 10ms cycle, but if you are sending such signals from VC to the PLC a bigger problem will be that the simulation time doesn’t follow the real time very accurately.

The communication happens and the PLC runs in real (wall clock) time, but your simulation signals would be in simulation time, which can run faster or slower than real time. In the “real time” simulation mode if something blocks the simulation thread for e.g. 500 ms (including UI interactions), the simulation will quickly catch up, resulting in a “burst” of signal values which the PLC won’t be able to receive even if they were all sent out.