Siemens S7-1200 - SGN_GET (Query RS-232 Signals) Instruction

Communication processor and Modbus TCP
12.3 Point-to-point (PtP) communication
S7-1200 Programmable controller
System Manual, 03/2014, A5E02486680-AG
699
Parameter and type
Data type
Description
ERROR OUT Bool When TRUE, shows that the last request was completed with errors. Also,
when this output is TRUE, the STATUS output will contain related error codes.
STATUS OUT Word Error code (Default value: 0)
See Common parameters for Point-to-Point instructions (Page 684) for
communication status codes.
Note
You might want to use the RCV_RST instruction to be sure the message buffers are c
lear
following a communications error, or after changing a communication parameter such as the
baud rate. Executing RCV_RST causes the module to clear all of the internal message
buffers. After clearing the message buffers, you can be assured that when you
r program
executes a subsequent receive instruction, the messages it returns are new messages and
not old messages from some time prior to the RCV_RST call.
12.3.3.8
SGN_GET (Query RS-232 signals) instruction
Table 12- 28 SGN_GET (Get RS232 signals) instruction
LAD / FBD
SCL
Description
"SGN_GET_DB"(
REQ:=_bool_in_,
PORT:=_uint_in_,
NDR=>_bool_out_,
ERROR=>_bool_out_,
STATUS=>_word_out_,
DTR=>_bool_out_,
DSR=>_bool_out_,
RTS=>_bool_out_,
CTS=>_bool_out_,
DCD=>_bool_out_,
RING=>_bool_out_);
SGN_GET reads the current states of RS232
communication signals.
This function is valid only for the RS232 CM.
1
STEP 7 automatically creates the DB when you insert the instruction.