Siemens SIMATIC S7-200 - Transmit, Receive

SIMATIC Instructions
9-186
S7-200 Programmable Controller System Manual
A5E00066097-02
Transmit, Receive
The Transmit instruction invokes the transmission of the
data buffer (TBL). The first entry in the data buffer
specifies the number of bytes to be transmitted. PORT
specifies the communication port to be used for
transmission.
The XMT instruction is used in Freeport mode to transmit
data by means of the communication port(s).
The format of the XMT buffer is:
The Receive instruction initiates or terminates the
Receive Message service. You must specify a start and
an end condition for the Receive box to operate.
Messages received through the specified port (PORT)
are stored in the data buffer (TBL). The first entry in the
data buffer specifies the number of bytes received.
Transmit: Error conditions that set ENO = 0: SM4.3
(run-time), 0006 (indirect address),
0009 (simultaneous XMT/RCV on port 0),
000B (simultaneous XMT/RCV on port 1),
CPU not in Freeport mode.
Receive: Error conditions that set ENO = 0: SM86.6 and SM186.6 (RCV
parameter error), SM4.3 (run-time), 0006 (indirect address), 0009 (simultaneous
XMT/RCV on port 0), 000B (simultaneous XMT/RCV on port 1), CPU not in
Freeport mode.
Inputs/Outputs Operands Data Types
TABLE VB, IB, QB, MB, SB, SMB, *VD, *AC, *LD BYTE
PORT Constant (0 for CPU 221, CPU 222, CPU 224; 0 or 1 for CPU 226) BYTE
L
A
D
S
T
L
XMT TBL, PORT
RCV TBL, PORT
XMT
EN
TBL
PORT
F
B
D
RCV
EN
TBL
PORT
ENO
ENO
222
224
✓✓✓
221 226
✓