Sensor Faults - Bacharach MGS-550 User Manual

MGS-550 Fixed Gas Detector
Code
0040
5.3.5

Sensor Faults

NOTICE
Sensor faults (for diagnostic attributes D-07 to D-10) may be decoded using the following table. Note that
several faults may be reported at the same time (see section 5.3.1:
more information). For example, fault code "0003" is a combination of fault codes 0001 (No sensor
signal) and 0002 (sensor board hardware fault). See D-07 through D-10.
NOTICE
Code
0000
0001
0002
0004
0008
0010
0020
0040
0080
0100
42
1.800.561.8187
Non-Critical
Possible Causes
Fault
Either current Possible wiring,
loop open connection, and/or
termination issue exists.
Analog output is set to 4
to 20 mA and loop is
open.
If a sensor fault occurs during a gas alarm condition, then the fault overrides the alarm
condition for that sensor (i.e., the alarm state(s) for that sensor "de-assert" and the
display shows "E 100"). Similarly, if a critical fault occurs, then all active alarm conditions
will "de-assert".
If a "last fault" attribute (D-08 or D-10) indicates that a fault has occurred at some point in
time, but the corresponding "current fault" attribute (D-07 or D-09) shows no fault, then
the problem has self-healed and no service action is required.
Sensor Fault
No Fault
No sensor signal
Sensor board hardware
fault
EEPROM checksum fault
Zero adjust out of range
Span adjustment out of
range
Input voltage fault
Microprocessor fault
Software fault
RS485 receiver fault
www.
Verify proper communications settings for the
network. Refer to section 4.4.5: Modbus
Configuration (MB-xx) on page 35 for more
information.
A possible hardware problem may exist.
Contact the factory.
Wire pin 3 to 4 or pin 5 to 6 on analog output
4 to 20 mA terminal. (See section 3.4.1:
Preparations on page 12.)
Check the integrity of the 4 to 20 mA
connections to the interface PCB
Possible Causes
Cannot detect sensor
Cannot read EEPROM or analog
front end
Error reading EEPROM
Field zero adjustment exceeds
limits
Field span adjustment exceeds
limits
Power supply voltage out of range
MPU clock fault
Firmware error
Receiver buffer full ( message too
.com
Remedy
Hexadecimal Format
on page 39 for
Remedy
Check all connections in
the sensing head.
Check connections to the
interface board.
Check all connections in
the sensing head.
Replace sensor module.
Perform zero adjustment
Perform span adjustment
Call service
Call service
Power-cycle. If it re-
occurs then call service
Power-cycle. If it re-
P/N: 1100-1000 Version 1
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