Depending on the hardware configuration, the protection relay can be equipped with one or several UART-based serial communication ports. The communication ports can be either galvanic (RS-485, RS-232) or fiber optic. The protection relay uses serial ports and drivers as different types of serial communication protocol links.
Serial ports are called COM1, COM2 and so on, depending on the number of serial ports in the relay hardware configuration. Each COM port driver has its own setting parameters found via the LHMI in (n= 1,2,…).
Since the same protection relay usually supports a variety of different communication hardware options, all COM port driver setting parameters are not relevant for every communication hardware type.
| COM parameter | Values | Hardware options |
|---|---|---|
| Fiber mode | 0 = No fiber |
Used in the fiber optic mode only. Note that ”No fiber “ mode is the same as the galvanic mode. |
| 1 = Fiber light ON/loop | ||
| 2 = Fiber light OFF/loop | ||
| 3 = Fiber light ON/star | ||
| 4 = Fiber light OFF/star | ||
| Serial mode | 0 = RS485 2wire |
For galvanic modes. RS-type depends on the communication card used. Note that this setting parameter is relevant only if Fiber mode is set to “No Fiber”. |
| 1 = RS485 4wire | ||
| 2 = RS232 no handshake | ||
| 3 = RS232 with handshake | ||
| CTS Delay | 0…60000 [ms] | RS232 mode only |
| RTS Delay | 0…60000 [ms] | RS232 mode only |
| Baudrate | 1 = 300 | All modes |
| 2 = 600 | ||
| 3 = 1200 | ||
| 4 = 2400 | ||
| 5 = 4800 | ||
| 6 = 9600 | ||
| 7 = 19200 | ||
| 8 = 38400 | ||
| 9 = 57600 | ||
| 10 = 115200 [bits/sec] |
Connection of a serial communication protocol to a specific serial port
The serial communication protocol (instance) settings include a setting parameter called Serial port n (n = protocol instance number). Setting options for this parameter are “COM1”, “COM2” and so on. The desired serial port for the protocol instance is selected through this parameter.