Operating hours counter
Block name
T32_OPERATING_HOURS
ST call
PROGRAM TEST_T32 VAR BOOL1,BOOL2,BOOL3: BOOL; TIME1,TIME2:TIME; DT1: DT; FB: LIB.HVAC.V1_0.T32_OPERATING_HOURS; END_VAR FB(BSET:= BOOL1, ENABLED:= BOOL2, IN:= BOOL3,TINIT:= TIME1, OUT=> TIME2, TSET=>DT1); END_PROGRAM
Library
LIB\HVAC
Version
V1.0
Description
The block measures total activity time of a binary input, or cumulated operating time of the connected aggregate (pump, fan, boiler).
Inputs
| Input | Type | Description | Default value |
| BSET | BOOL | Rising edge sets the counter to TINIT | False |
| ENABLE | BOOL | This input must be TRUE for the block to operate | False |
| IN | BOOL | Activity input | False |
| TINIT | TIME | “Starting” value after reset, usually 0 | 0 |
Outputs
| Output | Typ | Description |
| OUT | TIME | Total time the IN input was in TRUE |
| TSET | DT | Date and time of last reset (rising edge on BSET) as UTC |
Function
The block acts as a stopwatch. Time measuring start is activated by bringing the IN input to True, and stopped by bringing IN to False. The default state is set by a rising edge at bset, while the block writes the TINIT value to the OUT output rather than the cumulated time. This becomes the starting value for further cumulation. TSET records the rising edge time.
Application example
The variable PUMP1FB gives the pump operation signal. The cumulated time is recorded in T32 and of the total operation time exceeds PUMP_SERVICE_TIME, an alarm to call for service inspection is generated.