IOF_LB_ParityCheck

IOF_LB_ParityCheck 1:

The IOF_LB_ParityCheck function block reads the parity error counters of the Beckhoff Lightbus modules (e.g. BK2000). In contrast to the function block IOF_LB_ParityCheckWithReset, the counter states are not reset. The master maintains an 8-bit error counter for each module. These counters work without overflow. A maximum of 256 bytes of data, and therefore 256 counters, can be read. The number of error counters to be read is specified by the input variables LEN and DESTADDR. If, for instance, there are only 5 modules in the ring, then the DESTADDR parameter can be supplied with the address of a data buffer of 5 bytes, and the LEN parameter can be supplied with the value 5.

VAR_INPUT

VAR_INPUT
    NETID     : T_AmsNetId;
    DEVICEID  : UDINT;
    LEN       : UDINT;
    DESTADDR  : PVOID;
    START     : BOOL;
    TMOUT     : TIME := DEFAULT_ADS_TIMEOUT;
END_VAR

NETID: The network address of the TwinCAT computer on which the function is to be executed can be entered here (type: T_AmsNetID). If it is to be run on the local computer, an empty string can be entered.

DEVICEID: DeviceId specifies the device on which the function is to be executed. The device IDs are specified by the TwinCAT system during the hardware configuration.

LEN: The length in bytes of the data to be read.

DESTADDR: The address of the data buffer into which the parity data is to be written.

START: the block is activated by a positive edge at this input.

TMOUT: States the length of the timeout that may not be exceeded during execution of the command.

VAR_OUTPUT

VAR_OUTPUT
    BUSY    : BOOL;
    ERR     : BOOL;
    ERRID   : UDINT;
END_VAR

BUSY: When the function block is activated this output is set. It remains set until a feedback is received.

ERR: If an error should occur during the transfer of the command, then this output is set once the BUSY output was reset.

ERRID: Supplies the ADS error number when the ERR output is set.

Example:

PROGRAM MAIN
VAR
    IOF_LB_ParityCheck1 : IOF_LB_ParityCheck;
    ParityData          : ARRAY[1..256] OF BYTE;
    StartParityCheck    : BOOL;
    ParityCheck_Busy    : BOOL;
    ParityCheck_Err     : BOOL;
    ParityCheck_ErrId   : UDINT;
END_VAR

IOF_LB_ParityCheck 2:

Requirements

Development environment	Target platform	IO hardware	PLC libraries to be integrated (category group)
TwinCAT v3.1.0	None. This functionality is not supported by TwinCAT 3 at present!	Beckhoff Lightbus Master: C1220 ISA; FC200x PCI	Tc2_IoFunctions (IO)