​ Can a host computer software be connected to two PLCs at the same time?
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Can a host computer software be connected to two PLCs at the same time? It turns out that an upper-level software from Force Control was installed on one of the industrial computers, while the lower-level unit was a Siemens S200, with serial communication using the MODBUS protocol. Now, a Siemens S300 has been added on top of this, also using the MODBUS protocol. Two sets of PLCs are connected to the same industrial computer via different serial ports, but they are not connected to each other. I want the data from both PLCs to be displayed on the same interface of the upper-level software. However, after adding the new S300, the data communication with the original S200 stopped working, with a timeout error being reported. What could be the problem? (The new S300 data communication was successful).
Please help with this technical issue; I hope some experts can assist me
When adding 300 sites, was there a new protocol added? Choose Modbus
Are the addresses of the two PLC stations conflicting, with duplicate addresses?
It is feasible to do this: first use STEP7 to establish a master-slave relationship between the two PLCs, and then add both PLCs using the Modbus protocol in OPC, defining the address ranges for I/O points such as I, Q, and M
Sure. We use RS485 for communication, with the MODBUS protocol employed, and OPC is used for data acquisition at the field level. However, our PLC is of the S7-200 model
It should be fine; it’s possible that your address is conflicting
It’s definitely possible. As long as the interface address is different, that’s fine. Software must be driven by relevant drivers. As long as there are enough interfaces, more than a dozen sets are no problem.