In-Situ Aqua TROLL 400 Modbus and SDI-12 Reference Guide - Manual (Page 51)

7.2 Parameter Registers
Register Size
(registers)
Mode & Access Level
(R/W)
Data
Type
Description
pH
If the parameter value is read when the sensor is not plugged in, it returns the sentinel value and a Data
Quality ID of 7 (sensor communication error).
If the parameter value calculates to a value outside of the range 0 to 14 pH, it shall return the sentinel
value and a Data Quality ID of 3 (error).
1538 2 R1 float Measured value
1540 1 R1 ushort Parameter ID = 17 (pH)
1541 1 R1/W2 ushort Units ID
145 = pH (default)
1542 1 R1 ushort Data Quality ID
1543 2 R1/W3 float Off line sentinel value (default = 0.0)
1545 1 R1 16 bits Available Units = 0x0001 (1)
pH/mV
If the parameter value is read when the sensor is not plugged in, it shall return the sentinel value and a
Data Quality ID of 7 (sensor communication error).
1546 2 R1 float Measured value
1548 1 R1 ushort Parameter ID = 18 (pH mV)
1549 1 R1/W2 ushort Units ID
162 = mV (default)
1550 1 R1 ushort Data Quality ID
1551 2 R1/W3 float Off line sentinel value (default = 0.0)
1553 1 R1 16 bits Available Units = 0x0002 (2)
ORP/mV
If the parameter value is read when the sensor is not plugged in, it shall return the sentinel value and a
Data Quality ID of 7 (sensor communication error).
1554 2 R1 float Measured value
4556 1 R1 ushort Parameter ID = 19 (ORP)
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