Latch OTL
Turns the tag on and keeps it on. Use OTU to turn it off.
Global.AlarmOTL
| Tag | After two scans |
|---|---|
| Alarm | 1 |
How it works
Sets its BOOL operand to 1 while the rung is true. The operand stays 1 after the rung goes false, until an OTU clears it.
How it's used
Use OTL for something that must stay on after its cause goes away, such as an alarm.
Global.HighLevelXIC
Global.AlarmOTL
Global.ResetPBXIC
Global.AlarmOTU
| Tag | Value |
|---|---|
| HighLevel | 0 |
| ResetPB | 0 |
| Alarm | 1 |
HighLevel turned off. Alarm stayed on.
Operands
| Operand | Data type | Read or write |
|---|---|---|
| Tag | BOOL | Writes |
Common mistakes
- Forgetting an unlatch pathPlan the OTU that clears this same tag. A false latch rung does not clear it.
Learn it in a lesson
- Latch and unlatch coilsBeginner · 20 min