MAN-0093 Rev 0 Oxygen Sensor
June 2008
Net Safety Monitoring Inc.
11
SECTION 4: Output
4.1 Alarm and Fault Outputs
Sensor alarm and fault outputs are generated by the Millennium II transmitter series based on communication
with the sensor, however, some output values, registers, etc, may vary depending on sensor type.
4.1.1 Other Available Outputs
All available outputs are associated with the Millennium II series transmitters. These outputs are: Current
output, Relay Output, RS 485 Modbus (RTU) Output and HART Communication Output. Refer to the specific
Millennium II series transmitter manual for more information.
4.1.2 Modbus registers
Table 4 below shows the user accessible Modbus registers and meaning
Table 4: Modbus registers and meaning
Reg
#
Meaning
Readable
Writeable
40001
Concentration value as calculated by sensor
X
40002
Sensor status
X
40003
Sensor Temperature
X
40027
Sensor Range
X
X
40101
Resets the sensor
X
40102
Initialize zero & span *(
to calibrate sensor, enter channel #)*
X
40104
Zero only *(
to zero sensor, enter channel #)*
X
*
Note
: For the Millennium Basic transmitter enter ‘1’ in register 40102 to calibrate the sensor and ‘1’ in
register 40104 to Zero the sensor.
The Oxygen sensor only requires zeroing in ambient air for calibration, so either register 40102 or register
40104 may be used, as both commands will result in a proper calibration cycle.
