Stober PROFINET SD6, Руководство по эксплуатации

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11/2019 | ID 442710.03
10.3.2.1 RDREC and WRREC: Input and output parameters
In order to transfer acyclical parameter channel data, PROFINET offers the Read record and Write record functions. The
associated interfaces are controlled using the RDREC (read record) and WRREC (write record) SIMANTIC system function
blocks that operate asynchronously.
RDREC and WRREC contain special input and output parameters in a defined sequence. Both blocks communicate with the
IO devices in the network using the input and output parameters described below.
RDREC: Input and output parameters
The RDREC block reads a RECORD out of a hardware component addressed in the ID parameter.
REQ
STATUS
ID
LEN
BUSY
ERROR INDEX
MLEN
VALID
= B02E hex
RECORD
EN ENO
RDREC
Data Header “Response”
Fig. 9: RDREC system function block: Input and output parameters
Parameters Data type Declaration
EN BOOL IN Release input
REQ BOOL IN Transfer record (REQ = 1: Start transfer)
ID HW_IO IN Hardware ID for an IO device; is issued automatically and can be
read out using
TIA Hardware Manager > Device > Properties , for
example
INDEX DINT IN Record number (the associated value must always be B02E hex )
MLEN UINT IN Maximum length of the record to be transferred
ENO BOOL OUT Release output
VALID BOOL OUT Record was received and is valid
BUSY BOOL OUT Status of the reading (BUSY = 1: still not finished)
ERROR BOOL OUT Status of the reading (ERROR = 1: faulty)
STATUS DWORD OUT Status of the RDREC block or error information
LEN UINT OUT Length of the record that was read
RECORD Variant IN/OUT Record (consisting of data, see the chapter RDREC,
WRREC: RECORD [
}
50] )
Tab. 9: Parameters of the RDREC system function block