CPU ADAM 821x
Chapter 4 Deployment of the CPU 821xNET
ADAM 8000 Manual CPU 821x – Rev 1.1
4-15
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:
Handler block
Description
SEND
SFC230 Transmit a job from the CPU to the CP.
SEND_ALL
SFC236 Initiate a file transfer between the CPU and the CP.
RECEIVE
SFC231 Reception of an order from the CP.
RECEIVE_ALL
SFC237 Initiate a file transfer between the CPU and the CP.
FETCH
SFC232 The FETCH block requests data. FETCH initiates a
RECEIVE_ALL.
CONTROL
SFC233 The CONTROL block is used for a job-related status
request, i.e. the ANZW of a specific job is updated.
CONTROL_ALL
ANR=0 Request for the present job
RESET
SFC234 The RESET block initiates a reset of the job for the
specified connection.
RESET_ALL
ANR=0 RESET_ALL forces a full system reset of the CP.
SYNCHRON
SFC235 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.
PLC application
programming
Handler blocks
