In-Situ Aqua TROLL 400 Modbus and SDI-12 Reference Guide - Manual (Page 52)

Register Size
(registers)
Mode & Access Level
(R/W)
Data
Type
Description
4557 1 R1/W2 ushort Units ID
162 = mV (default)
4558 1 R1 ushort Data Quality ID
4559 2 R1/W3 float Off line sentinel value (default = 0.0)
4561 1 R1 16 bits Available Units = 0x0002 (2)
7.3 Calibration Registers—pH/ORP
These registers can be written only when the sensor is in the calibration mode. The probe will
return exception 0x92 (invalid sensor mode) if an attempt is made to write these registers when
the calibration mode is off. pH solution data must be written into the registers in order of
increasing pH.
Register Size
(registers)
Mode & Access Level
(R/W)
Data
Type
Description
1618 1 R1/W3 ushort
Number of pH calibration points 1, 2, or
3 (default = 1)
1619 2 R1/W3 float pH value of solution 1 (default = 0)
1621 2 R1/W3 float mV response in solution 1 (default = 0)
1623 2 R1/W3 float
Temperature of solution 1, T
1
in °C
(default = 25)
1625 2 R1/W3 float pH value of solution 2 (default = 0)
1627 2 R1/W3 float
mV response in solution 2, mV
2
(default = 0)
1629 2 R1/W3 float
Temperature of solution 2, T
2
in °C
(default = 25)
1631 2 R1/W3 float pH value of solution 3 (default = 0)
1633 2 R1/W3 float mV response in solution 3 (default = 0)
1635 2 R1/W3 float
Temperature of solution 3, T
3
in °C
(default = 25)
1637 2 R1/W3 float
Slope, m
1
in pH/mV
(default = -0.016903313)
1639 2 R1/W3 float Offset, b
1
in pH (default = 7.0)
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