The official Modbus Slave software is not free; it operates on a commercial license: Modbus Tools Evaluation Period:
Usually runs for a limited time (e.g., 10 minutes) before disconnecting.
If your network was working and suddenly stopped, a new device might have been added with a conflicting ID.
The term "Registration Key" is often used in configuration software (like SCADA, HMI, or OPC servers) to describe the process of "registering" a specific device on the network so the master knows where to send its requests.
: Go to the Help menu and select Register (or a similar activation option).
: Cracked versions often crash or fail to simulate timing-critical Modbus packets accurately, leading to wasted debugging time.