FB_BA_AntBlkg

Functional description

This function block prevents blocking of pumps or actuators after prolonged idle periods by issuing a switch-on pulse.
The maximum idle period before such a pulse is issued is determined by the value of the variable udiTiOffMin. For logging the idle time, the input bFdb must be linked to the operating feedback from the unit. The length of the pulse is parameterised with the variable udiTiImplLngt. The input bExe should be used if the blocking protection pulses are to be issued cyclically based on a switching schedule, rather than depending on the idle times. A rising edge at bExe immediately triggers output of a pulse to bQ. Generally, a pulse output only occurs if the function block at bEn is enabled.

VAR_INPUT

bEn           : BOOL;
bFdb          : BOOL;
bExe          : BOOL;
udiTiOffMin   : UDINT;
udiTiImplLngt : UDINT;

bEn: enable of the function block

bFdb: input for connecting the feedback signal of a motor or valve

bExe: rising edge forces a pulse output

udiTiOffMin: minimum switch-off time [s]: a pulse is issued once the time udiTiOffMin has elapsed without movement of the aggregate.

udiTiImplLngt: length of the blocking protection pulse [s] at bQ

VAR_OUTPUT

bQ             : BOOL;
udiRTiOffMin   : UDINT;
udiRTiImplLngt : UDINT;

bQ: output for the output of the pulse

udiRTiOffMin: remaining time [s] before the next pulse is issued in the absence of movement.

udiTiImplLngt: remaining residual time [s] of the pulse at bQ

Requirements