General Monitors IR4000M Installation manual

Model IR4000M
Multi-Point Monitor
Modbus programming guide
The information and technical data disclosed in
this document may be used and disseminated
only for the purposes and to the extent
specifically authorized in writing by General
Monitors.
Instruction Manual Modbus 07-08
General Monitors reserves the right to change
published specifications and designs without
prior notice.
MANIR4000MM
Part No. MANIR4000M Modbus
Revision A/07-08

Model IR4000M
ii
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Model IR4000M
iii
Table of Contents
MODEL IR4000M ..........................................................................................................................I
MULTI-POINT MONITOR..............................................................................................................I
MODBUS PROGRAMMING GUIDE .............................................................................................I
1.MODBUS RTU........................................................................................................................5
1.1Serial Communications Protocol for IR4000M..........................................................5
1.1.1Baud Rate.................................................................................................................5
1.1.2Data Format..............................................................................................................5
1.1.3Modbus Read Status Protocol (Query/Response)....................................................5
1.1.4Modbus Write Command Protocol (Query/Response) .............................................6
1.1.5Modbus Write Response Message...........................................................................6
1.2Function Codes Supported.......................................................................................7
1.2.1Exception Responses and Exception Codes............................................................7
1.3IR4000 Modbus Registers Summary Table..............................................................9
1.4IR4000 Modbus Base Registers Details.................................................................17
1.4.1Analog (0000h, Read-Only)....................................................................................17
1.4.2Operating Mode (0001h, Read)..............................................................................17
1.4.3Status Error (0002h, Read-Only)............................................................................18
1.4.4Model Type (0004h, Read-Only).............................................................................19
1.4.5Software Revision (0005h, Read-Only)..................................................................19
1.4.6Display LED Digits Two and Three (0006, Read-Only)..........................................19
1.4.7Display LED Digit One and Alarm/Warning LEDs (0007, Read-Only)..................19
1.4.8Number of Detectors Online (0009h, Read/Write)..................................................20
1.4.9Number of Votes (000Ah, Read/Write)...................................................................20
1.4.10Alarm Relay Settings (000Dh, Read/Write)............................................................20
1.4.11Warning Relay Settings (000Eh, Read/Write) ........................................................20
1.4.12Set CH1 Address (000Fh, Read/Write) ..................................................................21
1.4.13Baud Rate for CH1 (0010h, Read/Write)................................................................21
1.4.14Data Format for CH1 (0011h, Read/Write).............................................................21
1.4.15Modbus Address for CH2 (0012h, Read/Write)......................................................22
1.4.16Baud Rate for CH2 (0013h, Read/Write)................................................................22
1.4.17Data Format for CH2 (0014h, Read/Write).............................................................22
1.4.18Reset Alarm (0016h, Read/Write)...........................................................................22
1.4.19Total Receive Errors for CH1 (0017h, Read-Only).................................................23
1.4.20Function Code Errors for CH1 (0018h, Read-Only)...............................................23
1.4.21Starting Register Address Errors Errors for CH1 (0019h, Read-Only)...................23
1.4.22NVM Faults (001Ah, Read/Wrire)..........................................................................23
1.4.23CRC Hi Errors for CH1 (001Bh, Read-Only) ..........................................................24
1.4.24CRC Low Errors for CH1 (001Ch, Read-Only).......................................................24
1.4.25Overrun Errors for CH1 (001Dh, Read-Only) .........................................................24
1.4.26Framing Errors for CH1 (001Eh, Read-Only) .........................................................24
1.4.27Parity Errors for CH1 (001Fh, Read-Only)..............................................................24
1.4.28Total Receive Errors for CH2 (0021h, Read-Only).................................................24
1.4.29Function Code Errors for CH2 (0022h, Read-Only)...............................................24

Model IR4000M
iv
1.4.30Starting Register Address Errors Errors for CH2 (0023h, Read-Only)...................24
1.4.31CRC Hi Errors for CH2 (0025h, Read-Only)...........................................................25
1.4.32CRC Low Errors for CH2 (0026h, Read-Only)........................................................25
1.4.33Overrun Errors for CH2 (0027h, Read-Only)..........................................................25
1.4.34Framing Errors for CH2 (0028h, Read-Only)..........................................................25
1.4.35Parity Errors for CH2 (0029h, Read-Only)..............................................................25
1.4.36Clear Comm Errors for CH1 (002Ch, Read/Write) .................................................25
1.4.37Clear Comm Errors for CH2 (002Dh, Read/Write) .................................................25
1.4.38Enable HART or Modbus for CH2 (002Dh, Read/Write) ........................................25
1.5IR4000 Modbus Registers for IR400 Data..............................................................25
1.5.1Detector Analog Output (Read-Only)......................................................................25
1.5.2Operating Mode (Read-Only)..................................................................................26
1.5.3Status Error (Read-Only)........................................................................................27
1.5.4Gas Selection (Read-Only).....................................................................................28
1.5.5Model Type ( Read-Only)........................................................................................28
1.5.6Display ( Read-Only)...............................................................................................28
1.5.7Cal IO type (Read-Only) .........................................................................................28
1.5.8Solenoid State (Read-Only)....................................................................................28

Model IR4000M
5
1. MODBUS RTU
1.1 Serial Communications Protocol for IR4000M
The default Modbus setup from the factory is 19200 baud, 8-n-1 format. The default Modbus ID
for CH1 is 1, and for CH2 it is 2.These settings can be changed through the user interface
using the GMI magnet and selecting the SE menu item. Details can be found in the separate
Model IR4000M user manual; section 4.
The factory default settings for Modbus can be restored by connecting the RELAY RESET
terminal (TB2-7) to the power supply common and turning on power to the IR4000M. After 10
seconds, remove the connection between RELAY RESET and common.
1.1.1 Baud Rate
The Baud Rate is a selectable setting via the Modbus Communications Interface. The
selectable baud rates are 9600, 4800, or 2400 bits per second.
1.1.2 Data Format
The Data Format is a selectable setting via the Modbus Communications Interface. The
selectable data formats are as follows:
Data Bits Parity Stop Bit Format
8 None 1 8-N-1
8 Even 1 8-E-1
8 Odd 1 8-O-1
8 None 2 8-N-2
Table 1: Data Format
1.1.3 Modbus Read Status Protocol (Query/Response)
1.1.3.1 Modbus Read Query Message
Byte Modbus Range Referenced to IR400
1st Slave Address 1-247* (Dec) IR400 ID (Address)
2nd Function Code 03 Read Holding Registers
3rd Starting Address Hi** 00 Not Used by IR400
4th Starting Address Lo** 00-FF (Hex) IR400 Commands
5th No. of Registers Hi 00 Not Used by IR400
6th No. of Registers Lo 01 No. of 16 Bit Registers
7th CRC Hi 00-FF (Hex) CRC Hi Byte
8th CRC Lo 00-FF (Hex) CRC Lo Byte
Table 2: Modbus Read Query Message
*NOTE: Address 0 is reserved for broadcast mode and will not be supported at this time.
**NOTE: Start Address can be a maximum of 9999 Address Locations (0000-270E)

Model IR4000M
6
1.1.3.2 Modbus Read Response Message
Byte Modbus Range Referenced to IR400
1st Slave Address 1-247* (Dec) IR400 ID (Address)
2nd Function Code 03 Read Holding Registers
3rd Byte Count 02 No. of Data Bytes
4th Data Hi 00-FF (Hex) IR400 Hi Byte Status Data
5th Data Lo 00-FF (Hex) IR400 Lo Byte Status Data
6th CRC Hi 00-FF (Hex) CRC Hi Byte
7th CRC Lo 00-FF (Hex) CRC Lo Byte
Table 3: Modbus Read Response Message
1.1.4 Modbus Write Command Protocol (Query/Response)
1.1.4.1 Modbus Write Query Message
Byte Modbus Range Referenced to IR400
1st Slave Address 1-247* (Dec) IR400 ID (Address)
2nd Function Code 06 Preset Single Register
3rd Register Address Hi 00 Not Used by IR400
4th Register Address Lo 00-FF (Hex) IR400 Commands
5th Preset Data Hi 00-FF (Hex) IR400 Hi Byte Command Data
6th Preset Data Lo 00-FF (Hex) IR400 Lo Byte Command Data
7th CRC Hi 00-FF (Hex) CRC Hi Byte
8th CRC Lo 00-FF (Hex) CRC Lo Byte
Table 4: Modbus Write Query Message
*NOTE: Address 0 is reserved for broadcast mode and will not be supported at this time.
**NOTE: Start Address can be a maximum of 9999 Address Locations (0000-270E)
1.1.5 Modbus Write Response Message
Byte Modbus Range Referenced to IR400
1st Slave Address 1-247* (Dec) IR400 ID (Address)
2nd Function Code 06 Preset Single Register
3rd Register Address Hi 00 Not Used by IR400
4th Register Address Lo 00-FF (Hex) IR400 Commands
5th Preset Data Hi 00-FF (Hex) IR400 Hi Byte Command Data
6th Preset Data Lo 00-FF (Hex) IR400 Lo Byte Command Data
7th CRC Hi 00-FF (Hex) CRC Hi Byte
8th CRC Lo 00-FF (Hex) CRC Lo Byte
Table 5: Modbus Write Response Message

Model IR4000M
7
1.2 Function Codes Supported
Function Code 03 (Read Holding Registers) will be used to read status from the slave unit.
Function Code 06 (Preset Single Register) will be used to write a command to the slave unit.
1.2.1 Exception Responses and Exception Codes
1.2.1.1 Exception Response
In a normal communications query and response, the master device sends a query to the
IR400 and the IR400 receives the query without a communications error and handles the query
normally within the master device’s allowable timeout. The IR400 then returns a normal
response to the master. An abnormal communications produces one of four possible events:
1. If the IR400 does not receive the query due to a communications error, then no
response is returned from the IR400 and the master device will eventually process a
timeout condition for the query.
2. If the IR400 receives the query, but detects a communication error (CRC, etc.), then no
response is returned from the IR400 and the master device will eventually process a
timeout condition for the query.
3. If the IR400 receives the query without a communications error, but cannot process the
response to the master within the master’s timeout setting, then no response is
returned from the IR400 and the master device will eventually process a timeout
condition for the query. In order to prevent this condition from occurring the maximum
response time for the IR400 is 200 milliseconds. Therefore the MASTER’S Timeout
Setting should be set to 200 milliseconds or greater.
4. If the IR400 receives the query without a communications error, but cannot process it
due to reading or writing to a non-existent IR400 command register, then the IR400 will
return an exception response message informing the master of the error.
The exception response message (ref. No. 4 above) has two fields that differentiate it from a
normal response:
Byte Modbus Range Referenced to IR400
1st Slave Address 1-247* (Dec) IR400 ID (Address)
2nd Function Code 83 or 86 (Hex) MSB is set with Function Code
3rd Exception Code 01 - 06 (Hex) Appropriate Exception Code (See Below)
4th CRC Hi 00-FF (Hex) CRC Hi Byte
5th CRC Lo 00-FF (Hex) CRC Lo Byte
Table 6: IR400 Exception Response Message

Model IR4000M
8
1.2.1.2 Exception Code
Exception Code Field: In a normal response, the IR400 returns data and status in the data
field, which was requested in the query from the master. In an exception response, the IR400
returns an exception code in the data field, which describes the IR400 condition that caused the
exception. Below is a list of exception codes that are supported by the IR400:
Code Name Description
01 Illegal Function The function code received in the query is not an allowable
action for the IR4000.
02 Illegal Data Address The data address received in the query is not an allowable
address for the IR4000.
03 Illegal Data Value A value contained in the query data field is not an allowable
value for the IR4000.
04 Slave Device Failure An unrecoverable error occurred while the IR4000 was
attempting to perform the requested action.
05 Acknowledge The IR4000 has accepted the request and is processing it,
but a long duration of time will be required to do so. This
response is returned to prevent a timeout error from
occurring in the master.
06 Device Busy The IR4000 is engaged in processing a long-duration
program command. The master should retransmit the
message later when the slave is free.
Table 7: IR4000 Exception Codes

Model IR4000M
9
1.3 IR4000 Modbus Registers Summary Table
Register
Address
(Hex) Parameter Function Data
Type Data Range Access
0000H Analog Output 0-20mA current
output Numeric Value 0-65535 Dec, (scale to range
0-21.7mA) R
0001h Operating Mode Set/View operating
mode Bit Map See register description R/W
0002h Error Status View present error Bit Map See register
description R
0003h Misc. Fault For GMI use N/A N/A R
0004H Model Number View Model ID Numeric
Value 4002, etc. R
0005h Software Rev Software Revision 2 ASCII
characters A, B, etc. R
0006h Display digits 2
and 3 Shows present 2nd
and 3rd display digits
on IR4000 front
panel.
2 ASCII
characters Hi byte – 2nd
digit,
Lo byte – 3rd digit R
0007h Display LED digit
1 and Alarm /
Warning LEDs
Shows present front
panel display digit 1,
and Alarm / Warning
lights
1 ASCII
character
and LEDs
status
Hi byte – 1st
digit,
Lo byte : bit map
bit 3 – low LED
bit 4 - hi LED
R
0008h Line voltage Measured line voltage
* 10 Numeric Value 0-65535 R
0009h No. of Units
Online Defines no. of IR400
units connected Numeric Value 1-8 R/W
000Ah No. of Votes Determines how
many detectors must
reach alarm setpoint
to trigger
alarm/warning
Numeric
Value 1-8
R/W
000Bh Priority Fault Read main fault of the
IR4000 device Bit Map See register 0x0002
description R
000Ch HART
configuration Hi byte – AO range;
Lo byte – HART
enabled/disabled
Hi byte –
AO range;
Lo byte –
HART
enabled/di
sabled
Hi byte: 0 – hi
range,
1 – lo range,
Low byte: 0 –
disabled, 1 –
HART enabled
R/W
000Dh Alarm Relay
settings Read or change
settings for alarm Bit Map See description R/W

Model IR4000M
10
Register
Address
(Hex) Parameter Function Data
Type Data Range Access
000Eh Warning Relay
settings Read or change
settings for warning Bit Map See description R/W
000Fh Address for CH1 Set/View CH1
address Numeric Value 1-247 decimal R/W
0010h Baud Rate for
CH1 Set/View CH1 Baud
Rate (2400, 4800,
9600 19200)
Code 0, 1, 2, 3 R/W
0011h Data Format for
CH1 Set/View CH1 Data
Format (8N1, 8E1,
801, 8N2)
Code 0, 1, 2, 3 R/W
0012h Address for CH2 Set/View CH2
address Numeric Value 1-247 decimal R/W
0013h Baud Rate for
CH2 Set/View CH2 Baud
Rate (2400, 4800,
9600 19200)
Code 0, 1, 2, 3 R/W
0014h Data Format for
CH2 Set/View CH2 Data
Format (8N1, 8E1,
801, 8N2)
Code 0, 1, 2, 3 R/W
0015h Reserved N/A N/A N/A N/A
0016h Reset Alarm Resets latching
alarms Numeric Value 0 W
0017h Receive errors for
CH1 Number of CH1 total
receive errors Numeric Value 0-65535 decimal R
0018h Function code
errors for CH1 Number of CH1
function code errors. Numeric Value 0-65535 decimal R
0019h Starting Register
Address errors for
CH1
Number of CH1
Starting Register
Address errors.
Numeric
Value 0-65535 decimal R
001Ah NVM region Faults View/Reset NVM
pages fault Bit map See register
description R/W
001Bh CRC errors HI for
CH1 Number of CH1 CRC
HI errors Numeric Value 0-65535 decimal R
001Ch CRC errors LO for
CH1 Number of CH1 CRC
LO errors Numeric Value 0-65535 decimal R
001Dh Overrun errors
for CH1 Number of Overrun
errors for CH1 Numeric
Value 0-65535 decimal R
001Eh Framing errors for
CH1 Number of framing
errors for CH1 Numeric
Value 0-65535 decimal R
001Fh Parity errors for
CH1 Number of Parity
errors for CH1 Numeric
Value 0-65535 decimal R
0020h Reserved N/A N/A N/A R
0021h Receive errors for
CH2 Number of CH2 total
receive errors Numeric Value 0-65535 decimal R
0022h Function code
errors for CH2 Number of CH2
function code errors. Numeric Value 0-65535 decimal R

Model IR4000M
11
Register
Address
(Hex) Parameter Function Data
Type Data Range Access
0023h Starting Register
Address errors for
CH2
Number of CH2
Starting Register
Address errors.
Numeric
Value 0-65535 decimal R
0024h Reserved N/A N/A N/A N/A
0025h CRC errors HI for
CH2 Number of CH2 CRC
HI errors Numeric Value 0-65535 decimal R
0026h CRC errors LO for
CH2 Number of CH2 CRC
LO errors Numeric Value 0-65535 decimal R
0027h Overrun errors
for CH2 Number of Overrun
errors for CH2 Numeric
Value 0-65535 decimal N/A
0028h Framing errors for
CH2 Number of framing
errors for CH2 Numeric
Value 0-65535 decimal R
0029h Parity errors for
CH2 Number of Parity
errors for CH2 Numeric
Value 0-65535 decimal R
002Ah Reserved N/A N/A N/A N/A
002Bh Reserved N/A N/A N/A N/A
002Ch Clear Comm
errors for CH1 Clears CH1
communication errors Numeric Value See parameter description W
002Dh Clear Comm
errors for CH2 Clears CH2
communication errors Numeric Value See parameter description W
002Eh Reserved N/A N/A N/A N/A
002Fh Reset Events Clears events of
resets event flag Numeric Value 0 - Clear Events, 1 - Resets Event
Happened flag W
0030h Run Time hi High word of Run
Time in Seconds Numeric Value 0-65535 decimal R/W
0031h Run Time low Low word of Run
Time in Seconds Numeric Value 0-65535 decimal R/W
0032h Real Time Clock
Year, Month Read/Set year and
month of RTC Numeric Value 1 –99 year, 1–
12 month R/W
0033h Real Time Clock
Day, Hour Read/Set day and
hour of RTC Numeric Value 1 – 31 day,
0 – 23 hour R/W
0034h Real Time Clock
Minute, Second
Read/Set minutes
and seconds of
RTC
Numeric
Value 0 – 59 minutes 0 – 59 seconds R/W
0035h Power Cycled
Flag Time Reset After
power Cycled Numeric Value 0 = Time not Reset, 1 =
Time Reset R
0036h Event Index Index of Logged
Events Numeric Value 0 - 9 R/W
0037h Running Time
Hi Running Time Hi
for Warning Event
log entries
Numeric
Value 0 - 65535 R

Model IR4000M
12
Register
Address
(Hex) Parameter Function Data
Type Data Range Access
0038h Running Time
Low Running Time Low
for Warning Event
log entries
Numeric
Value 0 - 65535 R
0039h Clock Time Hi Hi byte = year, Lo
byte month:
Warning clock time
Numeric
Value 1 –99 year, 1– 12 month R
003Ah Clock Time Mid Hi byte = Day, Lo
byte Hour: Warning
clock time
Numeric
Value 1 – 31 day, 0 – 23 hour R
003Bh Clock Time Low Hi byte = Minute,
Lo byte second:
Warning clock time
Numeric
Value 0 – 59 minutes 0 – 59 seconds R
003Dh Reserved Reserved Numeric
Value 0 R
003Ch Reserved Reserved Numeric
Value 0 R
003Eh Warning Event
Count Total Warning
Event Count Numeric Value 0 - 65535 R
003Fh Running Time Hi Running Time Hi for
Alarm Event log
entries
Numeric
Value 0 - 65535 R
0040h Running Time
Low Running Time Low for
Alarm Event log
entries
Numeric
Value 0 - 65535 R
0041h Clock Time Hi Hi byte = year, Lo
byte month: Alarm
clock time
Numeric
Value 1 –99 year, 1– 12 month R
0042h Clock Time Mid Hi byte = Day, Lo
byte Hour: Alarm
clock time
Numeric
Value 1 – 31 day, 0 – 23 hour R
0043h Clock Time Low Hi byte = Minute, Lo
byte second: Alarm
clock time
Numeric
Value 0 – 59 minutes 0 – 59 seconds R
0044h Reserved Reserved Numeric
Value 0 R
0045h Reserved Reserved Numeric
Value 0 R
0046h Alarm Event
Count Total Alarm Event
Count Numeric Value 0 - 65535 R
0047h Running Time Hi Running Time Hi for
Fault Event log
entries
Numeric
Value 0 - 65535 R
0048h Running Time
Low Running Time Low for
Fault Event log
entries
Numeric
Value 0 - 65535 R

Model IR4000M
13
Register
Address
(Hex) Parameter Function Data
Type Data Range Access
0049h Clock Time Hi Hi byte = year, Lo
byte month: Fault
clock time
Numeric
Value 1 –99 year, 1– 12 month R
004Ah Clock Time Mid Hi byte = Day, Lo
byte Hour: Fault clock
time
Numeric
Value 1 – 31 day, 0 – 23 hour R
004Bh Clock Time Low Hi byte = Minute, Lo
byte second: Fault
clock time
Numeric
Value 0 – 59 minutes 0 – 59 seconds R
004Ch Fault Code See Table 9 Numeric
Value 0 R
004Dh Reserved Reserved Numeric
Value 0 R
004Eh Fault Event Count Total Fault Event
Count Numeric Value 0 - 65535 R
004Fh Running Time Hi Running Time Hi for
Maintenance Event
log entries
Numeric
Value 0 - 65535 R
0050h Running Time
Low Running Time Low for
Maintenance Event
log entries
Numeric
Value 0 - 65535 R
0051h Clock Time Hi Hi byte = year, Lo
byte month:
Maintenance clock
time
Numeric
Value 1 –99 year, 1– 12 month R
0052h Clock Time Mid Hi byte = Day, Lo
byte Hour:
Maintenance clock
time
Numeric
Value 1 – 31 day, 0 – 23 hour R
0053h Clock Time Low Hi byte = Minute, Lo
byte second:
Maintenance clock
time
Numeric
Value 0 – 59 minutes 0 – 59 seconds R
0054h Reserved Reserved Numeric
Value 0 R
0055h Reserved Reserved Numeric
Value 0 R
0056h Maintenance
Event Count Total Maintenance
Event Count Numeric Value 0 - 65535 R
0057h Running Time Hi Running Time Hi for
Calibration Event log
entries
Numeric
Value 0 - 65535 R
0058h Running Time
Low Running Time Low for
Calibration Event log
entries
Numeric
Value 0 - 65535 R

Model IR4000M
14
Register
Address
(Hex) Parameter Function Data
Type Data Range Access
0059h Clock Time Hi Hi byte = year, Lo
byte month:
Calibration clock time
Numeric
Value 1 –99 year, 1– 12 month R
005Ah Clock Time Mid Hi byte = Day, Lo
byte Hour: Calibration
clock time
Numeric
Value 1 – 31 day, 0 – 23 hour R
005Bh Clock Time Low Hi byte = Minute, Lo
byte second:
Calibration clock time
Numeric
Value 0 – 59 minutes 0 – 59 seconds R
005Ch Calibration code Calibration code Numeric
Value 1 – zero, 2 - calibration R
005Dh Reserved Reserved Numeric
Value 0 R
005Eh Calibration Event
Count Total Calibration
Event Count Numeric Value 0 - 65535 R
005Fh Event happened
flag Read if any event happened Code 0 – no events;
1-event
happened R
DETECTOR’S REGISTERS
Detector 1 Registers
0070h Analog Output 1 0-20mA current
output
For IR400 unit 1
Numeric
Value 0-65535 Dec (scale to range 0-
21.7mA) R
0071h Mode 1 View operational
mode for IR400 unit 1 Bit Map See parameter description R/W
0072h Status Error 1 View present error
for IR400 unit 1 Bit Map See parameter
description R
0073h Gas Choice 1 View gas chosen for
IR400 unit 1 Code 0-8 R
0074h Model 1 View model number
for IR400 unit 1 Numeric Value 2200, etc. R
0075h Display 1 Show LED digits 2
and 3 for IR400 unit 1 2 ASCII characters % LEL or Fault code
F1 to FF or
device status
(SU, AC or CP)
R
0076h % of Blockage 1 Show level of beam
blockage for IR400
unit 1
Numeric
Value 0-5000 R
0077h Cal IO type 1 Show type of
calibration input for
IR400 unit 1
Code 0 – LED switch, 1
–manual
solenoid , 2 -
ARGC
R/W

Model IR4000M
15
Register
Address
(Hex) Parameter Function Data
Type Data Range Access
0078h Solenoid State 1 Solenoid
Enabled/Disabled for
IR400 unit 1
Code 10 – Solenoid On
20 – Solenoid Off
30 – Solenoid
disabled
R/W
0079h Reserved Reserved N/A N/A N/A
007Ah Reserved Reserved N/A N/A N/A
007Bh Reserved Reserved N/A N/A N/A
007Ch Reserved Reserved N/A N/A N/A
007Dh Reserved Reserved N/A N/A N/A
007Eh % of Full Scale Show % of full scale
for IR400 unit 1 Numeric Value 0 – 99 R
007Fh Reserved Reserved N/A N/A N/A
Detector 2 Registers
0080h Analog Output 2 0-20mA current
output
For IR400 unit 2
Numeric
Value 0-65535 Dec (scale to range 0-
21.7mA) R
0081h Mode 2 View operational
mode for IR400 unit 2 Bit Map See parameter description R/w
0082h Status Error 2 View present error
for IR400 unit 2 Bit Map See parameter
description R
0083h Gas Choice 2 View gas chosen for
IR400 unit 2 Code 0-8 R
0084h Model 2 View model number
for IR400 unit 2 Numeric Value 2200, etc. R
0085h Display 2 Show LED digits 2
and 3 for IR400 unit 2 2 ASCII characters % LEL or Fault code
F1 to FF or
device status
(SU, AC or CP)
R
0086h % of Blockage 2 Show level of beam
blockage for IR400
unit 2
Numeric
Value 0-5000 R
0087h Cal IO type 2 Show type of
calibration input for
IR400 unit 2
Code 0 – LED switch, 1
–manual
solenoid , 2 -
ARGC
R/W
0088h Solenoid State 2 Solenoid
Enabled/Disabled for
IR400 unit 2
Code 10 – Solenoid On
20 – Solenoid Off
30 – Solenoid
disabled
R/W
0089h Reserved Reserved N/A N/A N/A
008Ah Reserved Reserved N/A N/A N/A
008Bh Reserved Reserved N/A N/A N/A
008Ch Reserved Reserved N/A N/A N/A
008Dh Reserved Reserved N/A N/A N/A

Model IR4000M
16
Register
Address
(Hex) Parameter Function Data
Type Data Range Access
008Eh % of Full Scale 2 Show % of full scale
for IR400 unit 2 Numeric Value 0 – 99 R
008Fh Reserved Reserved N/A N/A N/A
0090 -
009F Detector 3 Registers
00A0-
00AF Detector 4 Registers
00B0-
00BF Detector 5 Registers
00C0-
00CF Detector 6 Registers
00D0-
00DF Detector 7 Registers
00E0-
00EF Detector 8 Registers

Model IR4000M
17
1.4 IR4000 Modbus Base Registers Details
1.4.1 Analog (0000h, Read-Only)
A Read returns a value that is proportional to the Analog output current. The
value returned is a 16-bit binary value, in the range from 0-65535 decimal. The
decimal value must be scaled in proportion to an Analog current value from 0-
21.7mA.
1.4.2 Operating Mode (0001h, Read)
This register reports the current operating mode for the IR4000 base unit. A
Read command to this register returns the present IR4000M mode, represented
by the enabled bits. The following table shows the Mode associated with each
bit in the 16-bit register.
Table 8 Bitmap for Mode
Bit 7 6 5 4 3 2 1 0
Mode Not
Used
Initial
Mode
(Start-
up)
Detector
Gas
Check
Detector
Calibra-
tion
Detector
Zeroing Alarm l Warning
vel Run Mode
Bit Value 80 hex
128 dec 40 hex 64 dec 20 hex 32 dec 10 hex 16 dec 8 hex 8 dec 4 hex 4 dec 2 hex 2 dec 1 hex 1 dec
Bit 15 14 13 12 11 10 9 8
Mode Not Used Not Used Not Used Not Used Not Used Not Used Not
Used Not Used
Bit Value 8000 hex
32768
dec
4000 hex
16384
dec
2000 hex
8192 dec 1000 hex 4096 dec 800 hex 2048 dec 400 hex 1024 dec 200 hex 512 dec 100 hex 256 dec
1.4.2.1 Mode Descriptions
•Run Mode. Normal operation mode for all connected IR400 units, with LEL
measurement taking place.
•Warning Level. The IR400s have equaled or exceeded the votes configured
to trigger the relays for a Warning level gas.
•Alarm Level. The IR400s have equaled or exceeded the votes configured to
trigger the relays for an Alarm level gas.
•Detector Zeroing. One or more detectors are zeroing
•Detector Calibration. One or more detectors are in calibration
•Detector Gas Check. One or more detectors are in gas check mode.
•Startup Mode. This tells the user the IR4000 is starting up. The detector
takes typically 2 minutes to start.

Model IR4000M
18
1.4.3 Status Error (0002h, Read-Only)
A Read command returns the bit map for any Error that is presently occurring,
The following table shows the errors that are represented by each bit in the
register.

Model IR4000M
19
Table 9 Bitmap for IR4000 Status Error
Bit Position 3 2 1 0
Error Low Line Gas Left Fault NVM Fault Misc. Fault
Bit Value 8 hex / 8 dec 4 hex / 4 dec 2 hex / 2 dec 1 hex / 1 dec
Bit Position 7 6 5 4
Error Detector Non-
critical Fault Detector Critical Fault Fail to Complete Setup Wire Shortage
Bit Value 80 hex / 128 dec 40 hex / 64 dec 20 hex / 32 dec 10 hex / 16 dec
Bit Position 11 10 9 8
Error Comm. Error with
Detector 4 Comm. Error with Detector 3 Comm. Error with Detector 2 Comm. Error with Detector 1
Bit Value 800 hex / 2048 dec 400 hex / 1024 dec 200 hex / 512 dec 100 hex / 256 dec
Bit Position 15 14 13 12
Error Comm. Error with
Detector 8 Comm. Error with Detector 7 Comm. Error with Detector 6 Comm. Error with Detector 5
Bit Value 8000 hex / 32768 dec 4000 hex / 16384 dec 2000 hex / 8192 dec 1000 hex / 4096 dec
1.4.4 Model Type (0004h, Read-Only)
A Read returns the model type for the base.
1.4.5 Software Revision (0005h, Read-Only)
A read returns the software revision of the IR4000, which is two ASCII
characters.
1.4.6 Display LED Digits Two and Three (0006, Read-Only)
A Read returns the two rightmost ASCII character that would appear on the
IR4000 front panel. Bits 8-15 hold the contents of the second ASCII character,
and bits 0-7 hold the contents of the third ASCII character.
1.4.7 Display LED Digit One and Alarm/Warning LEDs
(0007, Read-Only)
A Read returns the leftmost ASCII-coded digit from the IR4000 front panel, along
with the status of the Alarm and Warning LEDs, as shown in the following table.
Bits 8-15 hold the contents of the first ASCII digit, which is often the IR400 unit
number. Bits 0-7 indicate the state of the Alarm and Warning LEDS, as follows:
•Bit 4 is set if the Alarm LED is ON
•Bit 3 is set if the Warning LED is ON

Model IR4000M
20
1.4.8 Number of Detectors Online (0009h, Read/Write)
Returns (via Read command) and sets (via Write command) the number of
IR400 detectors connected to this IR4000. Writing to this register is equivalent to
setting the Number of Detectors using the IR4000 menu options
1.4.9 Number of Votes (000Ah, Read/Write)
Returns (via Read command) and sets (via Write command) the “Number of
Votes” required to trigger the Alarm and Warning relays that go to local alarm
devices. Writing to this register is equivalent to setting the number of votes using
the IR4000 menu options
NOTE: The default setting is one. Maximum number of votes is equal to number
of detectors online
1.4.10 Alarm Relay Settings (000Dh, Read/Write)
A Read command returns the present Alarm settings of the IR4000. A Write
command changes the settings to the requested values.. 1 in bit 12 means the
output is Latching, a 0 means it is Non-Latching. A 1 in the 11th bit position
means the output is normally Energized; a 0 means it is normally De-Energized.
The lower byte is the alarm setpoint. The Alarm setpoint cannot be set below the
Warning setpoint.
NOTE: The maximum alarm setting for the IR4000 is 60%.
Factory default is 60% FS, latching, de-energized.
1.4.10.1 Exceptions
Returns an Exception Code 03 (illegal data) in the Exception Response message
if an illegal data is being written
1.4.11 Warning Relay Settings (000Eh, Read/Write)
A Read command returns the present Warning settings of the IR4000. A Write
command changes the settings to the requested values.. 1 in bit 12 means the
output is Latching, a 0 means it is Non-Latching. A 1 in the 11th bit position
means the output is normally Energized; a 0 means it is normally De-Energized.
The lower byte is the Warning setpoint.. The Warning setpoint cannot be set
above the Alarm setpoint.
NOTE: The maximum Warning setting for the IR4000 is 60%.
Factory default is 30% FS, non-latching, de-energized.
1.4.11.1 Exceptions
Returns an Exception Code 03 (illegal data) in the Exception Response message
if an illegal data is being written.