Ampcontrol Gasguard 2 - Modbus Communications; GG2 Detector Removal; Register Map

Ampcontrol Pty Ltd – ABN 28 000 915 542
GG2 COMMUNICATIONS USER MANUAL
GG2B032 Version 1 – JULY/2020
Uncontrolled Copy - Refer to Ampcontrol Website for Latest Version
Page 18 of 22
APPROVED FOR EXTERNAL DISTRIBUTION
– PROPERTY OF AMPCONTROL PTY LTD
– NOT TO
BE REPRODUCED IN PART
5 MODBUS COMMUNICATIONS
5.1 GG2 Detector Removal
If Modbus is activated and the detector is removed, all bit fields will go to all zeros and all numerical
values will go to 0xFFFF. The setpoint flag bits will go high (1) and are exceptions to the previous rule.
5.2 Register Map
All values can be assumed to be the Modbus default endianness, big-endian. Any exceptions to this will
be noted in the Format column.
Safety Registers
SCADA* - These registers/bits must be monitored and included in the trip permissives for all safety
system applications when this protocol is selected.
Register
Description
R/W
Detail
Format
SCADA*
1
Detector gas reading
permyriad - unaffected by
telemetry test
R
Permyriad of full scale,
see Error! Reference s
ource not found.Error!
Reference source not
found.
Signed Int

2
Bit-inverted Detector gas
reading permyriad -
unaffected by telemetry test
R
Permyriad of full scale,
See Error! Reference s
ource not found.Error!
Reference source not
found.
Signed Int, bit
inversion
3
Heartbeat
R
Increments on each
cycle, nominally every
100ms.
Unsigned Int

4 – bit 0
Safety Word – system fault
R
system fault
bit

4 – bit 1
Safety gas value invalid i.e.
reg 1
R
Safety gas value invalid
bit

Operational Registers
SCADA* - These registers/bits must be monitored and included in the trip permissives for all safety
system applications when this protocol is selected.
Register
Description
R/W
Detail
Format
SCADA*
5
Detector gas reading
permyriad - may be forced
by telemetry test.
R
Permyriad of full scale,
see Error! Reference s
ource not found.Error!
Reference source not
found.
Signed Int
6 – bit 0
SP1 flag
R
1 = flag set
bit
6 – bit 1
SP2 flag
R
1 = flag set
bit
6 – bit 2
SP3 flag
R
1 = flag set
bit
6 – bit 3
Cal cup on
R
1 = cup on
bit
6 – bit 4
Calibration due (every 6
months)
R
1 = calibration due
bit
6 – bit 5
T90 test due (every 31
days)
R
1 = T90 test due
bit
6 – bit 6
Detector present
R
1 = detector present
bit
6 – bit 7
4-20mA loop activation
R
1 = 4-20mA loop active
bit