65-2658XL-CH4-4 M2A-XL Transmitter Operator’s Manual
Chapter 8: RS-485 Modbus Output
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Using the M2A-XL in a 4-wire Modbus System
Although the M2A-XL is a 2-wire Modbus RTU device, it can be used with a 4-wire Modbus
controller if the system wiring is modified as follows:
• Connect the controller’s TxD0 and RxD0 wires together and use this connection as the 2-
wire Modbus D0 signal.
• Connect the controller’s TxD1 and RxD1 wires together and use this connection as the 2-
wire Modbus D1 signal.
• Connect these D0 and D1 signals and the common wire from the controller to the 2-wire
Modbus Network of M2A-XLs.
Modbus Mode
Modbus Mode allows you to configure various parameters relating to the Modbus setup of the
M2A-XL. Modbus Mode includes a 5-minute time-out feature. If you do not press a control
button for 5 minutes, the M2A-XL automatically returns to normal operation.
NOTE:
If the M2A-XL returns to normal operation because of a time-out, it enters a warm-up
period just as it does when it is first turned on.
1. While in normal operation, simultaneously press and hold the DOWN/NO and ENTER
buttons for 5 seconds to enter Modbus Mode. Release the buttons when the following screen
appears.
2. To exit Modbus Mode, press and release the DOWN/NO button. The M2A-XL will return to
normal operation.
To continue in Modbus Mode, press and release the UP/YES button. The current
ENABLED/DISABLED setting will appear.
Set Up
Modbus?
