XFC_EL2212_V2

XFC_EL2212_V2 handles the output of a digital cam with the XFC time stamp terminal EL2212.

Note The function block XFC_EL2212_V2 replaces the function block XFC_EL2212, which is still included in the library for compatibility reasons.

The output of the data to the terminal takes place only shortly before reaching the timestamp of one of the outputs. Four PLC cycles are required for activation and acknowledgement of the outputs. Only then can a further edge change take place. The minimum time between two edge changes of the output signal is therefore four PLC cycles, in order to prevent errors or loss of precision. If the output signal is generated by a cam controller, a minimum cam width can be calculated from the maximum velocity and the PLC cycle time.

The outputs Output1 and Output2 cannot be used completely independently of each other since the activation takes place with only one timestamp. As a prerequisite, the switching edges of both channels must be sufficiently far apart. In this case, the respectively nearest timestamp is applied to the block.

Inputs

VAR_INPUT
    ForceWhenLate : BOOL; 
END_VAR

ForceWhenLate

If ForceWhenLate is TRUE, the output is activated even if the time stamp is already exceeded.
It is recommended to set ForceWhenLate to prevent the loss of a switching edge in case of fluctuations of the time signal.

Outputs

VAR_OUTPUT
    Error             : BOOL;
    ErrorID           : UDINT;
    ErrorOutputMissed : BOOL;
    PrecisionReduced  : BOOL;
END_VAR

Error	Becomes TRUE if an error occurs.
ErrorID	If an error output is set, this parameter supplies an error number.
ErrorOutputMissed	The exact switching point defined by TimeStamp could not be adhered to and the initial state remains unchanged. If ForceWhenLate is TRUE, the initial state is always output and ErrorOutputMissed does not become TRUE.
PrecisionReduced	The exact switching point defined by TimeStamp could not be adhered to; the initial state was output with a delay. PrecisionReduced should be regarded as a warning. It can only become TRUE if ForceWhenLate is TRUE.

Inputs/outputs

VAR_IN_OUT
    Output1       : OUTPUT_REF;
    Output2       : OUTPUT_REF;
    TrackOptions1 : TRACK_REF;
    TrackOptions2 : TRACK_REF;
    EL2212        : EL2212_IoInterface;
END_VAR

Output1	Output state for channel 1 of the Terminal. The data structure Output contains the calculated state of the digital output and the associated time stamp for the output at a digital XFC output terminal
Output2	Output state for channel 2 of the Terminal. The data structure Output contains the calculated state of the digital output and the associated time stamp for the output at a digital XFC output terminal.
TrackOptions1	The TrackOptions1 data structure contains the parameterization of Cam Track 1 for Output1.
TrackOptions2	The TrackOptions2 data structure contains the parameterization of Cam Track 2 for Output2.
EL2212	Process image of the terminal