Command Interface

5.1Command 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:

SDeactivate the filtering of the analog inputs for the CP 243±2 in the system data block of the S7±200 CPU.

SBy setting the bit CP_READY = ª1º in the status byte, the CP 243-2 signals that it is ready for operation after the power supply is turned on.

5-2

SIMATIC NET CP 243-2 AS-i Master

C79000-G8976-C142/02

Page 70
Image 70
Siemens CP 243-2 installation instructions Command interface of the CP, Command Buffer and Response Buffer