5 Noncyclical data exchange
26
a decision made as to whether a further poll cycle is required ("ID-PLC" different) or valid re-
sponse data were received ("ID-PLC" identical). The parameters that need to be transferred at
cyclical call-ups of RDREC appear in the table at the end of this section.
b) Acceptance of response data: As soon as a data exchange packet is received from the JUMO
IO device and the values for "ID-PLC" in the data structures for outgoing and incoming data ex-
change packets are identical, the data structure for incoming data exchange packets contains
the valid response data from the JUMO IO device. The data have to be copied from here to the
target before they are overwritten by another read request.
5.1.2 Programs for program controllers
Program memories must be split within a data exchange sequence over multiple partial data records and
transferred in succession. The individual partial data records are transferred packed in data exchange
packets. For the outgoing and incoming data exchange packets, data structures in the "Program data
transfer" format must be created in the IO controller as target and source memories. The data exchange
packets with the partial data records are transferred in succession within a data exchange sequence in
separate WRREC-RDREC cycles. To allow the "program data transfer" type data structures to be over-
written again during the WRREC-RDREC cycle, the content of these structures between the WRREC-
RDREC cycle is synchronized with a further data structure, which holds ready for sending all data of the
entire program memory to be transferred and/or accepts them at the point of receipt.This data structure
must be declared in the IO controller for both the incoming and outgoing direction with the "Editing mem-
ory" format. For the complete transfer of a program memory, up to 3 partial data records have to be trans-
ferred:
1) 1 partial data record for program names
2) up to 2 partial data records for program segments, each with up to 25 program sections
Parameterizing function blocks WRREC/RDREC
Input parameters for WRREC/
RDREC
Transfer values
Single-ID Multi-ID
LEN
(Length of the data to be written for
WRREC in bytes)
65 65
MLEN
(Maximum length of the data to be
read for RDREC in bytes)
ID
(Hardware detection of slots/subslots
to be addressed on the IO device)
Hardware detection of Slot 1 on JUMO IO devices (DeviceSta-
tusBlock)
INDEX
(Index of the target range for data ex-
change packets of JUMO IO devices)
201 202
RECORD
(Pointer on data points to be read/
written; with JUMO IO devices, data
structures for incoming and outgoing
data exchange packets are trans-
ferred.)
for WRREC: Pointer on the data structure for outgoing data ex-
change packets
for RDREC: Pointer on the data structure for incoming data ex-
change packets
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