You must make sure that the receive buffer is not read before the operation has been
completed since you could otherwise be reading could cause inconsistent data.
When the CPU changes to STOP mode,
n all newly received commands receive a negative acknowledgement.
n for commands that have already been received: all commands that have been
entered into the in receive queue receive a negative acknowledgement.
n all data blocks are discarded when a new start follows.
When the connection is terminated any operation that was entered into the receive queue
of this connection is discarded.
Exception: if this is the oldest operation in the queue that has already been recognized by
a SFC-call with EN_DT = 0 it can be transferred into the receive buffer by means of
EN_DT = 1.
If no error has occurred, RET_VAL contains:
n when EN_DT = 0/1 and NDA = 0: 7000h. In this case the queue does not contain a
data block.
n when EN_DT = 0 and NDA = 1, RET_VAL contains the length (in bytes) of the oldest
data block that was entered into the queue as a positive number.
n when EN_DT = 1 and NDA = 1, RET_VAL contains the length (in bytes) of the data
block that was copied into the receive bufferRD as a positive number.
Error information
The "real error information" that is contained in the table "specific error information" a. o.
may be classified as follows:
Value Description
809xh Error on the CPU where the SFC is being executed
80Axh Permanent communication error
80Bxh Error on the communication partner
80Cxh Temporary error
Specific Error information:
Value Description
0000h Processing completed without errors.
00xyh When NDA = 1 and RD <> NIL: RET_VAL contains the length of the received data block (when EN_DT
= 0) or the data block copied into RD (when EN_DT = 1).
7000h EN_DT = 0/1 and NDA = 0
7001h First call with REQ = 1: data transfer initiated; BUSY is set to 1.
7002h Intermediate call (REQ irrelevant): data transfer active; BUSY is set to 1.
Data consistency
Operating mode transition
to STOP mode
Termination of a connec-
tion
RET_VAL (Return value)
VIPA SPEED7
Integrated Standard
System Functions > SFC 66 - X_RCV - Receive data
HB00 | OPL_SP7 | Operation list | en | 18-30 707
To Next Page
Loading...
