Page 107 - Gas Detection Systems Training Manual

Modbus 3120 Unit Read/Write Registers
Unit Clock- Write New Time Registers
Unit Clock- Set New Time Now
Unit Diagnostics Control (force relays on/off, toggle LEDs to flash)
Unit- Place into Modbus listen only mode
Unit- Restore out of Modbus listen only mode
SEC 3120 Setup and Configuration
Connector Block P5
Pin7
Pin5 Pin4 Pin1
(Bottom View of SEC 3120- Relay Board Connectors)
SEC 3120 Modbus RS-485 Network Connections
Pin 5 (RS485 B) of the SEC 3120 power and communication connection block P5 is typically connected to a Modbus Master device (RX-) terminal in two-wire connections. For the EGX-100 Gateway, this would be Pin 4 of the RS485 connection block.
Pin 4 (RS485 A) of the SEC 3120 power and communication connection block P5 is typically connected to a Modbus Master device (RX+) terminal in two-wire connections. For the EGX-100 Gateway, this would be Pin 3 of the RS485 connection block.
The EGX-100 Gateway is connected to the Ethernet using its Ethernet port and 10/100 base T/TX cable to an Ethernet switch.
SEC 3120 16-bit Modbus Manual Page 6 Of 46 Sensor Electronics Corporation For Version 1.2 and above December 2012 P/N 1580282, Rev. 1, 20121228