IOF_LB_ParityCheckWithReset

IOF_LB_ParityCheckWithReset 1:

The function block IOF_LB_ParityCheckWithReset allows the parity error counter of Beckhoff Lightbus modules (e.g. the BK2000) to be read. The counters are then reset. Internally, an instance of the ADSREAD function block is called. 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    : DWORD;
    START       : BOOL;
    TMOUT       : TIME;
END_VAR

NETID: It is possible here to provide the AmsNetId of the TwinCAT computer on which the function to be executed. 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 Manager 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 function block is activated by a positive edge at this input.

TMOUT: States the length of the timeout that may not be exceeded by execution of the ADS 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 and acknowledgement is received.

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

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

Example of a call in FBD:

IOF_LB_ParityCheckWithReset1     : IOF_LB_ParityCheckWithReset;
ParityData                       : ARRAY[1..256] OF BYTE;
StartParityWithReset             : BOOL;
ParityReset_Busy                 : BOOL;
ParityReset_Err                  : BOOL;
ParityReset_ErrId                : UDINT;


IOF_LB_ParityCheckWithReset 2:

Requirements

Development environment

Target system type

IO hardware

PLC libraries to include

TwinCAT v2.7.0

PC (i386)

Beckhoff Lightbus Master: C1220 ISA; FC200x PCI

Standard.Lib; PLCSystem.Lib; TcPLCAds.Lib; TcPlcIoFunctions.Lib

TwinCAT v2.8.0

PC (i386)

Beckhoff Lightbus Master: C1220 ISA; FC200x PCI

TcIoFunctions.Lib

( Standard.Lib; TcBase.Lib; TcSystem.Lib; TcUtilities.Lib are included automatically )