Siemens SIMATIC CP 440, Руководство пользователя

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Programming Example – Standard Blocks
9-9
Point-to-point connection CP 440 Installation and Parameter Assignment
A5E00057742-02
“SEND_ERROR=1” program section:
If SEND_440 runs through with SEND_ERROR=1, the SEND_COUNTER_ERR
error counter is incremented in data word 2. The SEND_STATUS is copied,
because it is overwritten with 0 in the next run, which means it will not be possible
to read it out.
Description of the FC 22 (RECEIVE)
The “Enable Receive Data“ program section:
Before data can be received, the receive enable (RECV_EN_R) at block
RECV_440 must be set to “1”.
“RECV_NDR=1” program section:
When RECV_NDR is set, new data has been received and the
RECV_COUNTER_OK receive counter is incremented.
“RECV_ERROR=1” program section:
If execution is unsuccessful (i.e. if the error bit is set at the parameter output of
RECV_440), the RECV_COUNTER_ERR error counter is incremented. The
RECV_STATUS is copied, because it is overwritten with 0 in the next run and it will
thus not be possible to read it out.
All relevant values can be observed for test purposes in the variable table.
9.6.2 “CP440 1 CYC” Program Example
This example is set up identically to the example “CP440 SEND RECV”. However,
the FC 21 has been changed to allow a SEND job to be processed cyclically.