Manual
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Modbus Registers
Common Registers
Register Size
Mode &
Access Level
(R/W)
Data Type Description
9001 1 R/W ushort Device ID = 31 for RDO PRO-X
9002 2 R/W ulong Device serial number
9004 3 R/W time Manufacture date
Sensor Status Registers
Register Size
Mode &
Access Level
(R/W)
Data Type Description
0005 3 R1 time
Cap start time
0 = no cap
0008 3 R1 time
Replace cap
0 = no cap
8 = Service period exceeded or moderate abrasion
detected on cap
Sensor health diagnostics indicate when the RDO sensor has
been damaged in the field. If the sensor has sustained moderate
damage, the probe provides a D.O value that includes a warning.
The same warning is included with readings taken after the sensor
has reached its 24-month recommended lifespan.
However, if the sensor has been severely damaged, an error
message is shown and a D.O. value is not provided. This prevents
you from receiving an erroneous reading.