Note: In this manual the counterparts of the communication exchange are referred to as master/slave.
The protection relay can communicate with several protocol slaves sequentially. A protocol master communication entity which is configured to operate with a specific slave or group of slaves is called an instance.
There are two master instance scenarios:
- One slave - One master protocol instance - One protocol mapping. The protection relay is intended to operate toward one protocol slave unit. The protocol data mapping or data outlook can be modified freely once Modbus Master-specific function blocks have been added to ACT.
- Several slaves - One master protocol instance - One protocol mapping. The protection relay is intended to operate toward several protocol slaves. All slave units are listed in the same protocol data mapping or data outlook. The protocol mapping or data outlook can be modified freely once Modbus Master-specific function block has been added to ACT.