Table 4 modbus™ special registers – Detcon IR-700 User Manual
Page 32
Model IR-700
IR-700 Instruction Manual
Rev. 3.1
Page 28 of 40
FC
REG
Content Description
R/W
Content Definition
Value
Meaning
Range
03/
06
40012
Special #2
R/W
Function dependent on value of
40006 (See Special Register
03
40013
Special #3
R
Function dependent on value of
40006 (See Special Register
03/
06
40014
Special #4
R/W
Function defendant on value of
40006 (See Special Register
03
06
40015
40015
Calibration Status
Calibration Enable
R
W
0x0000
0x0001
0x0002
0x0003
0x0004
0x0001
0x0002
0x0008
0x0009
0x000A
0x000B
Idle
Zero Calibration Started
Span Calibration Started
Span Set
Span Calibration Unsuccessful
Set Zero
Set Span
Signal simulation mode
Set FP Bridge Voltage
Set TP Heater Power
Set IR Gain
03
40016
Read Text 1, first char in
L
R
Two Char of Gas/Units String
6
03
40017
Read Text 2
R
Two Char of Gas/Units String
6
03
40018
Read Text 3
R
Two Char of Gas/Units String
6
03
40019
Read Text 4
R
Two Char of Gas/Units String
6
03
40020
Read Text 5, last char in
H
R
Two Char of Gas/Units String
6
03
40021
Text null terminator in L
R
Two Char of Gas/Units String
6
1
Integer ranges from 1 all the way to 10,000.
2
Units are determined by “units” field in the “notation” string
3
Gas Reading times one (x 1) with units in notation string for “Low Range” = 0. Gas Reading times one (x 10) with units in notation string for “Low
Range” = 1. Gas Reading times one (x 100) with units in notation string for “Low Range” = 2.
4
Span Gas must be less than or equal to Detectable Range and is usually about ½ of it.
5
Fault status bits self-reset when fault clears
6
Text in ASCII, in order L byte, H byte, L byte… See field descriptions of notation string.
Gas/Units String
Character #
1
2
3
4
5
6
7
8
9
10
11
Description
Units
0x20
Gas Type
0x00
Units – This field is ‘PPM’, ‘PPB’, or ‘_ _ %’ (where ‘ _ ‘ is a space, 0x20).
0x20 – The units filed is terminated with an ASCII space (0x20)
Gas Type – This field contains the gas type of the cell. Any ASCII string is permissible
0x00 – The notation string is terminated with an ASCII null character
Table 4 Modbus™ Special Registers
REG
DM (40006 = 1)
FP (40006 = 2)
IR (40006 = 3)
TP (40006 = 4)
1
PI (40006 = 5)
40011
Low Range= 0, 1, 2
0: Range >25 (0 decimal place)
1: Range 10-25 (1 decimal place)
2: Range <10 (2 decimal place)
Gas Factor (R/W)
Range = 79 to 565
Gas Factor (R/W)
Range = 20 to 565
Heater Power
(mW) (R/W)
Low Range= 0, 1, 2
0: Range >25
1: Range 10-25
2: Range <10
40012
0x8XXX
0x0XXX
0xX000
0xX096
0xX0C8
0xX12C
Positive Polarity Cell
Negative Polarity Cell
Bias = 0mV
Bias = 150mV
Bias = 200mV
Bias = 300mV
Cal Factor (R/W)
Range = 79 to 565
Active Counts
Heater Voltage
(mV)
0x8XXX
0x0XXX
0xX000
0xX096
0xX0C8
0xX12C
Positive
Polarity
Cell
Negative
Polarity
Cell
Bias = 0mV
Bias = 150mV
Bias = 200mV
Bias = 300mV
40013
Gain Code
(integer between 0 & 15)
Bridge Current (mA)
Reference Counts
Sensor Resistance
(x100 Ω)
Gain Code
40014
Raw Counts 0-0xFFFF
(0x8000 = nominal 0)
Bridge Voltage (mV)
(Read only)
Range Divisor
1,10,100, or 1000
Heater Current
(mA )
Raw Counts
1
Only possible ranges are 20, 50, 100, 200. Modbus register 40001 will contain either 20, 50, 100, or 200, range divisor is not necessary.