Yokogawa Multi Channel Oxygen Analyzer System ZR22/AV550G - Manual (Page 42)

<6. IN-PROCESS OPERATION>
6-1
IM 11M12D01-61E
6. IN-PROCESS OPERATION
This section describes AV550G function block mode transitions and status changes during operation.
6.1 Mode Transition
If the function block mode is changed (from Auto) to O/S (Out_Of_Service), the function block is
stopped and a block alarm is generated.
If the function block mode is changed (from Auto) to Manual, the function block stops updating output
values. In this case it is possible to write desired output values to the OUT parameter.
However, the status of parameters cannot be changed.
6.2 Generation of Alarm or Error Status
6.2.1 AV550G Alarms
If the AV550G self-diagnostic functions detect an abnormality in the AV550G, a device alarm is
generated by the resource block. If an abnormality (block error) or process (value abnormal) alarm is
detected, the corresponding block generates an alarm.
6.2.2 Alarms and Events
An AV550G can report the following alarms or events as alerts:
Analog Alerts (Generated when a process value exceeds threshold)
By AI Block: Hi-Hi Alarm, Hi Alarm, Low Alarm, Low-Low Alarm
Discrete Alerts (Generated when an abnormal condition is detected)
By Resource Block: Block Alarm, Write Alarm
By Transducer Block: Block Alarm
By AI Block: Block Alarm
By DI Block: Block Alarm
By MAI Block: Block Alarm
By MAO Block: Block Alarm
Update Alerts (Generated when a important (restorable) parameter is updated)
By Resource Block: Update Event
By Transducer Block: Update Event
By AI Block: Update Event
By DI Block: Update Event
By MAI Block: Update Event
By MAO Block: Update Event
An alert has the following structure: