YASKAWA VIPA SPEED7 - SFB 52 - RDREC - Reading Record Set

14.2.20 SFB 52 - RDREC - Reading record set
The SFB 52 RDREC interface is identical to the FB RDREC defined in
the standard "PROFIBUS Guideline PROFIBUS Communication and
Proxy Function Blocks according to IEC 61131-3".
With the SFB 52 RDREC (read record) you can read a record set with the number INDEX
from a module that has been addressed via ID. Specify the maximum number of bytes
you want to read in MLEN. The selected length of the target area RECORD should have
at least the length of MLEN bytes. TRUE on output parameter VALID verifies that the
record set has been successfully transferred into the target area RECORD. In this case,
the output parameter LEN contains the length of the fetched data in bytes. The output
parameter ERROR indicates whether a record set transmission error has occurred. In this
case, the output parameter STATUS contains the error information. System dependent
this block cannot be interrupted!
The SFB 52 RDREC operates asynchronously, that is, processing covers multiple SFB
calls. Start the job by calling SFB 52 with REQ = 1. The job status is displayed via the
output parameter BUSY and bytes 2 and 3 of output parameter STATUS. Here, the
STATUS bytes 2 and 3 correspond with the output parameter RET_VAL of the asynchro-
nously operating SFCs (see also meaning of REQ, RET_VAL and BUSY with Asynchro-
nously Operating SFCs). Record set transmission is completed when the output param-
eter BUSY = FALSE.
Parameter Declaration Data type Memory block Description
REQ INPUT BOOL I, Q, M, D , L,
constant
REQ = 1:
Transfer record set
ID INPUT DWORD I, Q, M, D, L,
constant
Logical address of the module
For an output module, bit 15 must be set
(e.g. for address 5: ID: DW = 8005h).
For a combination module, the smaller of
the two addresses should be specified.
INDEX INPUT INT I, Q, M, D, L,
constant
Record set number
MLEN INPUT INT I, Q, M, D, L,
constant
Maximum length in bytes of the record set
information to be fetched
VALID OUTPUT BOOL I, Q, M, D, L New record set was received and valid
BUSY OUTPUT BOOL I, Q, M, D, L BUSY = 1: The read process is not yet ter-
minated.
ERROR OUTPUT BOOL I, Q, M, D, L ERROR = 1: A read error has occurred.
STATUS OUTPUT DWORD I, Q, M, D, L Call ID (bytes 2 and 3) or error code.
LEN OUTPUT INT I, Q, M, D, L Length of the fetched record set informa-
tion.
RECORD IN_OUT ANY I, Q, M, D, L Target area for the fetched record set.
Description
Operating principle
Parameters
VIPA SPEED7
Integrated Standard
System Function Blocks > SFB 52 - RDREC - Reading record set
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