FB_WriteBoolOnDelta

FB_WriteBoolOnDelta 1:

The function block enables event-driven writing of a variable of type BOOLEAN.

The FB_WriteBoolOnDelta function block checks cyclically whether the value at the bSignal input has changed. The cycle time for checking is determined by the parameter tCycleTime. If 0 s is given for tCycleTime, the input signal is examined during every PLC cycle. If a change is detected, the value of the signal is sent to the specified ADS device. The receiver is addressed by means of the AMS-NetId and the port number (see also ADS Device Identification). The position within the receiver is specified by the index group/index offset or by the symbol name. Usually this is the input image or the flags area.

If the bEnable input is set to FALSE, no further signal transmission is carried out.

VAR_INPUT

VAR_INPUT
    bEnable          :  BOOL := FALSE;
    sNetId           :  T_AmsNetId;
    nPort            :  T_AmsPort;
    nIdxGrp          :  UDINT;
    nIdxOffs         :  UDINT;
    sVarName         :  STRING;
    bSignal          :  BOOL;
    tCycleTime       :  TIME := t#0s;
    bSendNow         :  BOOL;
END_VAR

bEnable: Enable function block.

sNetId: AMS NetID of the ADS device to which the value is to be transmitted. (Type T_AmsNetId)

nPort: AMS port number of the ADS device to which the value is to be transmitted. (Type T_AmsPort)

nIdxGrp: Index group within the ADS device into which the value is to be transmitted.

nIdxOffs: Index offset within the ADS device into which the value is to be transmitted.

sVarName: Symbol name within the ADS device into which the value is to be transmitted.

bSignal: Variable whose value is to be transferred.

tCycleTime: Cycle time in which the input signal is examined to see that it has changed.

bSendNow: The value is transmitted immediately in response to a positive edge.

VAR_OUTPUT

VAR_OUTPUT
    bBusy            :  BOOL := FALSE;
    bLastSignal      :  BOOL;
    bError           :  BOOL := FALSE;
    nErrorId         :  UDINT := 0;
    nErrorCnt        :  UDINT := 0;
END_VAR

bBusy: The transmission is active.

bLastSignal: Most recently transmitted value.

bError: An error occurred during the transmission.

nErrorId: Error number if an error has occurred.

nErrorCnt: Number of transmission attempts that have returned faults.

Requirements

Development environment

required TC3 PLC library

TwinCAT v3.0.0

Tc2_DataExchange