Startup
7.3 Behavior of the CP 340 on Operating Mode Transitions of the CPU
PtP coupling and configuration of CP 340
Manual, 04/2011, A5E00369892-03
129
7.3
Behavior of the CP 340 on Operating Mode Transitions of the CPU
Introduction
Once the CP 340 has been started up, all data is exchanged between the CPU and the CP
340 by means of the function blocks.
CPU-STOP
In CPU-STOP mode, communication via the S7 backplane bus is not possible. Any active
CP-CPU data transmission, including both send and receive message frames, is aborted
and the connection is reestablished.
Data traffic at the RS 232C interface of the CP 340-RS 232C is continued with the ASCII
driver and the printer driver in the case of parameterization without flow control. In other
words, the current send request is completed. In the case of the ASCII driver, receive
message frames continue to be received until the receive buffer is full.
CPU Startup
At start-up, the CPU sends off the parameters generated with CP 340: Point-to-Point
Communication, Parameter Assignment parameterization interface. The CP 340 only
reparameterizes if the parameters have changed.
Through appropriate parameterization with the parameterizing software, you can have the
receive buffer on the CP 340 deleted automatically at CPU start-up.
CPU RUN
When the CPU is in RUN mode, sending and receiving are unrestricted. In the first FB cycles
following the CPU restart, the CP 340 and the corresponding FBs are synchronized. No new
P_SEND, P_RCV or P_PRINT FB is executed until this is finished.
Points to Note when Sending Message Frames, Printer Output
Transmission of message frames and printer output are possible only in CPU RUN mode.
If the CPU switches to STOP mode during CPU > CP data transmission, the P_SEND or
P_PRINT FB reports the error "current program interrupted, request aborted due to
BREAK/restart/reset" after restart.
Note
The CP 340 does not send data to the communications partner until it has received all data
from the CPU.
Содержание SIMATIC CP 340
Страница 6: ...Preface PtP coupling and configuration of CP 340 6 Manual 04 2011 A5E00369892 03 ...
Страница 10: ...Table of contents PtP coupling and configuration of CP 340 10 Manual 04 2011 A5E00369892 03 ...
Страница 186: ...Accessories and Order Numbers PtP coupling and configuration of CP 340 186 Manual 04 2011 A5E00369892 03 ...
Страница 190: ...Literature on SIMATIC S7 PtP coupling and configuration of CP 340 190 Manual 04 2011 A5E00369892 03 ...
Страница 200: ...Index PtP coupling and configuration of CP 340 200 Manual 04 2011 A5E00369892 03 ...