Rs-485 Modbus™ Protocol; Table 3: Modbus™ Registers - Teledyne 700 IR Series Instruction Manual

4 RS-485 Modbus™ Protocol
OLCT 700/710 detectors feature Modbus™ compatible communications protocol and are addressable
via the program mode. Communication is two wire, half duplex 485, 9600 baud, 8 data bits, 1 stop bit,
no parity, with the detector set up as a slave device. A master controller up to 1200 meters (4000 feet)
away can theoretically poll up to 256 different detectors. This number may not be realistic in harsh
environments where noise and/or wiring conditions would make it impractical to place so many devices
on the same pair of wires. If a multi-point system is being utilized, each detector should be set for a different
address. Typical address settings are: 01, 02, 03, 04, 05, 06, 07, 08, 09, 0A, 0B, 0C, 0D, 0E, 0F, 10,
11, etc.
Detector RS-485 ID numbers are factory default to 01. These can be changed in the field via the Operator
Interface described in Section 3.5.5 Set Serial ID.
The following section explains the details of the Modbus™ protocol that the OLCT 700/710 detector
supports.
Code 03 - Read Holding Registers is the only code supported by the transmitter. Each transmitter contains
6 holding registers which reflect its current status.
FC REG Content Description
03 40000 Device Type
03 40001 Read Detectable Range
06 40001 Write Detectable Range
03 40002 Read Concentration
03 06 40003 Read AutoSpan Level
40003 Write AutoSpan Level
03 40004 Read Sensor Life
03 40005 Read Fault Status Bits
03 40006 Read Model #
03 40007 Read Days Since Cal
03 40008 4-20 Current Output
mA x100
03 40009 Read Input Voltage V x100
NP700IRIMEN
Revision E.0
INFRARED GAS DETECTOR FOR COMBUSTIBLE AND CO
Table 3: Modbus™ Registers
R/W
Value
R 8 OLCT 700/710 Detector
1,2
R/W 100 For 0-100
10000 For 0-10000
3,2
R 1000 Bound by range. If > range, this value is in
fault.
4,2 R/W 50 Span gas at 50
R 85 For 85% sensor life
5 R 0x0001 Global Fault
0x0002 Auto Span Fault
0x0004 Temperature Fault
0x0008 4-20mA Fault
0x0010 Input Voltage Fault
0x0020 Memory Fault
0x0040 Processor Fault
0x0080 Clearing Fault
0x0100 Stability Fault
0x0200 Range Fault
0x0400 Sensor Fault
0x0800 Zero Fault
0x1000 Sensor Fault 2
0x2000 <reserved>
0x4000 In Calibration
0x8000 Communication Error
R 1, 2, 3, DM, FP, IR, TP, PID respectively
4, 5
R 29 29days
R 400 4.00mA
R 2400 24.00V
700 IR Series
Content Definition
Meaning
FP – Read only
2 TP – 20, 50, 100, 200
IR – 0 to 10000
FP – 5% to 95% of Range
(40001)
TP – 2% to 50% of Range
(40001)
IR – 5% to 95% of Range
(40001)
Range
2
GASES
USER MANUAL
Range
33