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7.2 Trouble Alarm Operation (Fault Alarm Operation)
When this detector detects an internal failure, it will activate a trouble alarm.
The master can detect a trouble alarm of a slave (this detector) by reading the device status
information at register address 40516.
Trouble alarm will be automatically cleared, when a problem is removed (self-resetting).
For the trouble alarm operation of the main unit, refer to 7-3 “Operation – Trouble
Alarm” of the PS-7-M series gas detector's instruction manual.
(1) Low flow rate
A minimum flow rate is not present.
There are two low flow rate patterns. When the flow rate is reduced due to a clogged filter or
excessive negative pressure, etc., the flow rate icon spins slowly (low flow rate 1). When the flow
rate is too low, the icon stops spinning, “FLOW” is shown on the LCD and a low flow rate alarm
activates (low flow rate 2).
For the information on the LCD, refer to 5-6 “LCD Indicator Icons” of the PS-7-M
series gas detector's instruction manual.
(2) Broken pyrolyzer wire (when detector uses a pyrolyzer)
A broken wire occurs.
(3) Sensor fault
The sensor’s zero level output is extremely low, or
A broken sensor wire occurs (applies to CHS-7 combustible gas sensor only).
The device status information (register address: 40516) is one word consisting of two bytes, Status
byte 1 (high-order byte) and Status byte 2 (low-order byte).
The trouble alarms are assigned to bits 2 to 5 of Status byte 1 as shown below.
Bit assignment (trouble alarms)
Trouble
alarm
Register name
Register
address
Data contents
Low flow
rate
Current value
(device status
information)
40516
0: Good /1: Not good
Status byte 1
bit7
bit0
1
bit5: Low flow rate 1
Status byte 1
bit7
bit0
1
bit4: Low flow rate 2
Broken
pyrolyzer
wire
0: Good /1: Not good
Status byte 1
bit7
bit0
1
bit3:
Broken pyrolyzer wire
Sensor fault
0: Good /1: Not good
Status byte 1
bit7
bit0
1
bit2: Sensor fault
NOTE
NOTE
