Communications
configuring
System- and communication configuring D7-SYS - SIMADYN D
3-157
Edition 12.2003
•
max. data quantity which can be transferred:
For internal data management and buffer mechanisms, the following
are required
- for received data sets, 2x data set length
- for sent data sets 3x data set length
The sum of the required bytes for all of the write and read data sets
may not exceed the above mentioned memory size of 114688 bytes!
Example:
Max. number of write and read data sets, each 240 bytes:
114688 bytes / (5 * 240 bytes) = 95.5733
A maximum of 95 write- and 95 read data sets, each with 240 bytes can
be configured.
“
S
ystem
F
unction
C
alls” SFC are used in the SIMATIC-CPU for data set
transfer:
•
write
SFC 58
data set (to the FM 458)
•
read
SFC 59
to the data set (from FM 458)
This coupling type is configured on the FM 458 in 3 steps:
1. Establish the coupling:
Configure a central communications block
@CPB
(from the
“SpezKomm” block family) to initialize and monitor the data set
coupling.
2. Define the send and receive data sets:
A function block must be configured for each data set (telegram):
CRV
to receive,
CTV
to send
Data/entries at the CRV/CTV connections:
−
CTS = FM458.
P_B
Connection is connected to the P bus coupling:
CFC entry:
Mark the CTS/righthand mouse key/connection to the operand.
The configured module name (default “FM458”) appears in the
selection list for the module to be connected.
−
AR / AT = ‘channelname.datasetnumber”
Any name (max. 6 characters) and separated by a point, the data
set number, which corresponds to the RECNUM info/data in the
SCF58/59 calls.
Value range:
2 to 127
for the send and receive data set
If several data sets are used, the channel names must be unique,
i.e. they must be different.
SIMATIC S7
access with SFC
FM 458 with “virtual
connections”
