Sensor Electronics SEC Millenium Series Instruction And Operation Manual page 347

To change these settings, you must adjust them using the user interface controls
on the SEC 3120 unit. When making changes out of the box, the following order of
changes should be made (remove the unit from the communication bus until everything is
set the way you desire):
1. Sensor Role- Change the sensor role in the Network Modbus Settings menu. Save
the changes first and exit the menus before returning to make further changes.
2. Sensor Relay Mode- Change the sensor relay mode in the Relay Settings menu.
Save the changes first and exit the menus before returning to make further
changes.
3. Modbus Network Mode- Change the Modbus Network mode in the Network
Modbus Settings menu. Save the changes first and exit the menus before returning
to make further changes. Do NOT try to change the network IDs or RS485 bus
settings without exiting the menus first!
4. Modbus Network IDs- Set the Modbus Network ID(s) (Addresses based on the
network mode chosen above, using the Network Modbus ID menu. Save the
changes first and exit the menus before returning to make further changes.
5. RS485 Bus Settings- Set the RS485 Communication Settings to your desired line
settings in the Network RS485 Bus Settings Menu. Changes are applied
immediately after you choose to save them, therefore make sure these settings are
correct before connecting the unit to the bus. Make sure you have no conflicting
network IDs with any other Modbus devices on the bus.
Relevant Screens you may see in order of operation, to change the unit to the
following settings (example):
 Sensor Role - Unique
 Relay Logic Mode- OR
 Modbus Network Mode- Single
 Modbus Network IDs
 RS485 Bus Settings- SEC Alternate (9600 baud, 1 stop bits, no parity)
First, we must examine how the user interface works on the 3120, is described on the
following pages:
SEC 3120 16-bit Modbus Manual
For Version 1.2 and above
Page 8 Of 46 Sensor Electronics Corporation
December 2012 P/N 1580282, Rev. 1, 20121228