Use Of Function Blocks For Reading And Controlling The Rs 2332C Secondary Signals - Siemens SIMATIC CP 340 User Manual

Communication using function blocks

6.5 Use of function blocks for reading and controlling the RS 2332C secondary signals

6.5 Use of function blocks for reading and controlling the RS 2332C
secondary signals
Introduction
The functions available for reading and controlling the RS 232C secondary signals are
V24_STAT (FC 5) for checking the interface statuses and V24_SET (FC 6) for
setting/resetting the interface outputs.
Checking the interface states of the CP 340
The V24_STAT FC reads the RS 232C secondary signals from the CP 340 and makes them
available to the user in the block parameters. The V24_STAT FC is called statically (without
conditions) for data transmission in the cycle or alternatively in a time-controlled program.
The RS 232C secondary signals are updated each time the function is called (cyclic polling).
The CP 340 updates the status of the inputs/outputs in a timebase of 20 ms. The
inputs/outputs are constantly updated independently of this.
The binary result BR is not affected. The function does not issue error messages.
The LADDR parameter defines the CP 340 to be addressed.
Block call
STL representation
CALL V24_STAT
LADDR: =
DTR_OUT: =
DSR_IN: =
RTS_OUT: =
CTS_IN: =
DCD_IN: =
RI_IN: =
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LAD representation
PtP coupling and configuration of CP 340
Manual, 04/2011, A5E00369892-03