Siemens CP 243-2 - Manual (Page 70)

Command Interface
5-2
SIMATIC NET CP 243-2 AS-i Master
C79000-G8976-C142/02
5.1 Command interface of the CP 243-2
Command Buffer and Response Buffer
Command calls are made to the CP 243-2 from within the user program. You
specify the command call in a command buffer and start the job.
The command buffer is in the analog output area of the CP 243-2 (for example
starting at AQW0 if the CP 243-2 is plugged in directly beside an S7-200 CPU).
Depending on the command to be executed (see Section 5.2), the response data
occupy banks 2 to 15 in the analog output area of the CP 243-2.
On completion of the job, the job status and any response data are made available
in a response buffer.
The response buffer is in the analog input area of the CP 243-2 (for example
starting at AIW0 if the CP 243-2 is plugged in directly beside an S7-200 CPU).
Depending on the command that was executed, the response data occupy banks 2
to 15 in the analog input area of the CP 243-2.
Requirements
Remember that the following requirements must be met before a command call is
sent from within the user program:
S
Deactivate the filtering of the analog inputs for the CP 243–2 in the system data
block of the S7–200 CPU.
S By setting the bit CP_READY = “1” in the status byte, the CP 243-2 signals
that it is ready for operation after the power supply is turned on.