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STOBER
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11/2019 | ID 442710.03
10.3.2.2
RDREC and WRREC: Acyclical communication flow
The following diagrams clarify the communication flow of the RDREC and WRREC system function blocks.
Read record flow
1. WRREC [Header Request (Request_ID = 0x01)]
2. RDREC
3. RDREC [Header Response (Response_ID = 0x01) + Data]
3. RDREC [Header Response (Response_ID = 0x81) + Data]
Either
parameter value
or
error
Preparation of
parameter value
IO controller
IO device
Fig. 11: RDREC flow
During RDREC, be aware that each parameter service begins with a read record request and ends with a read record
response.
Write record flow
1. WRREC [Header Request (Request_ID = 0x02) + Data ]
2. RDREC
3. RDREC [Header Response (Response_ID = 0x02) + Data]
3. RDREC [Header Response (Response_ID = 0x02) + Data]
Either
OK
or
error
Internal
processing
IO controller
IO device
Fig. 12: WRREC flow
