Equipment Failure Detector
Function Block Name
Lib.Mervis.v1_1.FailureDetector
Description
Core block used to evaluate equipment operation and detect failures.
Required Project References
- Lib.Mervis
Block Usage Restrictions
None - current standard block.
Usage in ST
program test
var
failuredetector: lib.mervis.v1_1.FailureDetector;
end_var
failuredetector();
end_program
Input and Output Description
| Inputs | Name | Data type | Retain | Must be connected | Description |
| Demand | bool | No | Yes | Operating demand | |
| Feedback | bool | No | Yes | Running feedback | |
| Failure | bool | No | Yes | Failure signal input | |
| Delay | time | No | No | Waiting interval for active running feedback | |
| CountLimit | uint | No | No | Number of consecutive failures required to trigger a persistent alarm | |
| Timeout | time | No | No | Delay before restarting |
| Outputs | Name | Data type | Description |
| FailureOutput | AlarmTrigger | Alarm output |
Detailed Function Description
The block evaluates equipment operation and generates a trigger condition for alarm generation. When the Demand command is active, the Feedback signal is monitored. If it does not become active within the time specified by the Delay input, an alarm is generated.
An alarm is also generated when the Failure input is activated. If the number of consecutive failures (separated by activation and deactivation of the command) is less than CountLimit, an alarm with automatic reset is generated. Otherwise, manual intervention is required to reset the alarm.
The alarm remains active for the period specified by the Timeout parameter. If startup is successful, the failure counter is reset.
The block generates alarms with the following priorities:
- 32 - alarm requiring external intervention
- 33 - alarm with automatic reset