Siemens SIMATIC CP 440 Manual page 82

Configuring and Parameterizing the CP 440
Receive Buffer on the CP
The table below describes the parameters for the CP receive buffer.
Table 5-13 Receive Buffer on the CP (3964(R) procedure)
Parameter
Delete CP Receive During power up or during transition of
Buffer on Startup the CPU from STOP to RUN the CP
receive buffer is deleted.
Buffered Receive You can specify the number of receive
Message Frames message frames to be buffered in the CP
receive buffer or to use the whole buffer.
If you use the whole buffer of 2000 bytes,
the number of buffered receive message
frames depends only on the length of the
frames.
If you specify "1" here, disable the
"Prevent Overwriting" parameter and
cyclically read the received data from the
user program, a current message frame
will always be sent to the CPU.
Prevent You can use this parameter to prevent
Overwriting data in the receive buffer being
overwritten when the buffer is full.
Further Information
You can find further information on handling the receive buffer under "Receive
Buffer on the CP 440" in Section 2.2.2.
5-18
Description
Point-to-point connection CP 440 Installation and Parameter Assignment
Value Range Default Value
Yes No
No
1 to 10 Use Whole
Buffer
Use Whole Buffer
Yes Yes
No
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