Adam 821x Manual page 78

CPU ADAM 821x
PLC application
programming
Handler blocks
Handler block
SEND
SEND_ALL
RECEIVE
RECEIVE_ALL
FETCH
CONTROL
CONTROL_ALL
RESET
RESET_ALL
SYNCHRON
ADAM 8000 Manual CPU 821x – Rev 1.1
To enable the PLC to process connect requests, it requires an active PLC
application program on the CPU. This uses the handler blocks (SEND,
RECEIVE, ...) that are included in the CPU 821xNET amongst others.
The PLC-program also requires that a communication channel be specified
first between the CPU and the CP ("synchronization"). This function is
performed by the SYNCHRON block.
Transmission and reception is initiated by means of SEND and RECEIVE.
A data transfer is initiated by means of SEND_ALL resp. RECEIVE_ALL.
Error messages will appear in the indicator word.
A description of the handler blocks is available in this manual in the chapter
on "Integrated handler blocks".
The following table lists the respective handler blocks:
SFC230
SFC236
SFC231
SFC237
SFC232
SFC233
SFC233 + ANR=0
SFC234
SFC234 + ANR=0
SFC235
Chapter 4 Deployment of the CPU 821xNET
Description
Transmit a job from the CPU to the CP.
Initiate a file transfer between the CPU and the CP.
Reception of an order from the CP.
Initiate a file transfer between the CPU and the CP.
The FETCH block requests data. FETCH initiates a
RECEIVE_ALL.
The CONTROL block is used for a job-related status
request, i.e. the ANZW of a specific job is updated.
Request for the present job
The RESET block initiates a reset of the job for the
specified connection.
RESET_ALL forces a full system reset of the CP.
During start-up, SYNCHRON provides the synchroniza-
tion between CPU and CP. At the same time the page
frame is erased and the block size between PLC and
CP is negotiated. Active data communications may only
occur via synchronized page frames.
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