Sensor Electronics SEC 3000, Instruction And Operation Manual

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SEC 3120 16-bit Modbus Manual Page 26 Of 46 Sensor Electronics Corporation
For Version 1.2 and above December 2012 P/N 1580282, Rev. 1, 20121228
Function Code 03 - Read Holding Registers
The following holding registers (4X references) are supported by the SEC 3120
for one or multiple sequential function code 03 read 16-bit binary operations (multiple
read operations must be sequential starting at the specified valid holding register address
in the read list). Broadcast mode is not supported for this function.
Table 7: Function Code 03 Read Holding Registers
Internal
Register
Address Holding
Register
Address Function Code 03- Read Sensor Register Description
(Data bits and Parameter Specifics)
x = sensor number (1 - 8)
2x00 42x01 *Scaled Sensor Gas Concentration
2x01 42x02
Bit-mapped Sensor Operating Status:
Bit 0,1: alarm status (0,0 = no alarm, 0,1 = low
alarm, 1,0 = mid alarm, 1,1 = high alarm.
Bit 2: fault alarm status (1 = fault, 0 = no)
Bit 3: self test (1 = testing, 0 = not)
Bit 4: cell test warning (1 = have warning, 0 = no)
Bit 5: init/warm (1 = init/startup, 0 = idle/run)
Bit 6: sensor missing (1 = missing, 0 = ok)
Bit 7: calibration (1 = calibrating, 0 = not)
Bit 8 - 15: **Sensor Status Code (8 bit integer)
2x02 42x03
Sensor Firmware Version (1 – 255)
2x03 42x04 *Scaled Low Sensor Alarm Set Point
2x04 42x05 *Scaled Mid Sensor Alarm Set Point
2x05 42x06
*Scaled High Sensor Alarm Set Point
2x06 42x07 *Scaled Sensor Calibration Value
2x07 42x08 *Scaled Sensor Range Value
2x08 42x09
Sensor Gas Factor
*These registers are scaled by Sensor Gas Factor (2x08). To obtain the real floating point
Query Exception Status Message
Field Name Example (Hex)
Slave Address 11
Function Code 07
CRC Low Byte 4C
CRC High Byte 22
Response Exception 1
Field Name Example (Hex)
Slave Address 11
Function Code 87
Exception Code 01
CRC Low Byte 83
CRC High Byte F5