In-Situ Aqua TROLL 400 Modbus and SDI-12 Reference Guide - Manual (Page 75)

8.30 Serial Communication Configuration
The 16 bits in this register are mapped to the communication parameters. The bits are mapped
as follows:
Bits Description
0 Modbus Transmission Mode
0 = RTU (default)
1=ASCII
1,2 & 3 Baud Rate Id
0 = 9600 (mandatory)
1 = 19200 (default)
2 = 38400
3 = 57600
4 = 115200
5 = 128000
6 = 230400
7 = 256000
4 Data Bits
0 = 7 data bits
1 = 8 data bits (default)
5,6 Parity Bits
0 = Even (default)
1 = Odd
2 = None
7 Stop Bits
0 = 1 Stop Bit (default)
1 = 2 Stop Bits
8-15 Unassigned
When the communication configuration register is changed, the Modbus response will be sent to
the Master at the current configuration (mode, baud, parity, data bits…etc). After the response
has been sent to the Master, the device will switch to the new settings.
The Master software must switch communications to the new settings after receiving a positive
Modbus response to the write message. The Master software should confirm the new settings
by reading back the device address and communication configuration register.
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