Modbus TCP wraps the Modbus RTU frame in a TCP/IP packet and transmits over standard Ethernet using RJ45 connectors. Port 502 is the registered Modbus TCP port for SCADA and HMI communications.
| Pin | Name | Function | Type |
|---|---|---|---|
| 1 | TX+ | Ethernet transmit positive | BUS |
| 2 | TX- | Ethernet transmit negative | BUS |
| 3 | RX+ | Ethernet receive positive | BUS |
| 6 | RX- | Ethernet receive negative | BUS |