Function block instructions for counting events. Each counter instance creates child variables (.CU/.CD, .Q, .PV, .CV).
| Instruction | Description |
|---|---|
| CTU | Count-Up Counter - increments on each activation |
| CTD | Count-Down Counter - decrements on each activation |
All counter types share the same set of child variables:
| Variable | Type | Description |
|---|---|---|
.CU / .CD |
BOOL | Count-up / Count-down input |
.Q |
BOOL | Output signal (TRUE when count condition is met) |
.PV |
INT | Preset value (target count) |
.CV |
INT | Current value (current count) |