Siemens S7-1200 - SEND_PTP (Transmit Send Buffer Data) Instruction

Communication processor and Modbus TCP
12.3 Point-to-point (PtP) communication
S7-1200 Programmable controller
694 System Manual, 03/2014, A5E02486680-AG
12.3.3.5
SEND_PTP (Transmit send buffer data) instruction
Table 12- 19 SEND_PTP (Send Point-to-Point data) instruction
LAD / FBD
SCL
Description
"SEND_PTP_DB"(
REQ:=_bool_in_,
PORT:=_uint_in_,
BUFFER:=_variant_in_,
LENGTH:=_uint_in_,
PTRCL:=_bool_in_,
DONE=>_bool_out_,
ERROR=>_bool_out_,
STATUS=>_word_out_);
SEND_PTP initiates the transmission of the data
and transfers the assigned buffer to the
communication interface. The CPU program
continues while the CM or CB sends the data at the
assigned baud rate. Only one send operation can
be pending at a given time. The CM or CB returns
an error if a second SEND_PTP is executed while
the CM or CB is already transmitting a message.
1
STEP 7 automatically creates the DB when you insert the instruction.
Table 12- 20 Data types for the parameters
Parameter and type
Data type
Description
REQ IN Bool Activates the requested transmission on the rising edge of this transmission
enable input. This initiates transfer of the contents of the buffer to the Point-to-
Point communication interface. (Default value: False)
PORT IN PORT After you install and configure a CM or CB communication device, the port
identifier appears in the parameter helper drop-list available at the PORT box
connection. The assigned CM or CB port value is the device configuration
property "hardware identifier". The port symbolic name is assigned in the
"System constants" tab of the PLC tag table. (Default value: 0)
BUFFER IN Variant This parameter points to the starting location of the transmit buffer. (Default
value: 0)
Note: Boolean data or Boolean arrays are not supported.
LENGTH
1
IN UInt Transmitted frame length in bytes (Default value: 0)
When transmitting a complex structure, always use a length of 0.
PTRCL IN Bool This parameter selects the buffer as normal point-to-point or specific Siemens-
provided protocols that are implemented within the attached CM or CB.
(Default value: False)
FALSE = user program controlled point-to-point operations. (only valid option)
DONE
OUT
Bool
TRUE for one scan, after the last request was completed with no error
ERROR
OUT
Bool
TRUE for one scan, after the last request was completed with an error
STATUS
OUT
Word
Execution condition code (Default value: 0)
1
Optional parameter: Click the arrow at the bottom of a LAD/FBD box to expand the box and include this parameter.
While a transmit operation is in progress, the DONE and ERROR outputs are FALSE. When
a transmit operation is complete, either the DONE or the ERROR output will be set TRUE to
show the status of the transmit operation. While DONE or ERROR is TRUE, the STATUS
output is valid.