Transferring Data Sets - Siemens SIMADYN D FM 458 User Manual

4.3.4 Transferring data sets

If extremely large quantities of data are to be transferred, e.g. for
Application
visualization applications (WinCC), or if data have to be transferred
between SIMATIC and FM 458 for an extremely high number of drives.
• Memory available on the P bus: 114688 bytes (0x1C000 hex), for
Features,
limit values
• max. 125 read and 125 write data sets
• max. length per data set (telegram): 240 bytes
• max. data quantity which can be transferred:
Example:
Max. number of write and read data sets, each 240 bytes:
A maximum of 95 write- and 95 read data sets, each with 240 bytes can
be configured.
SIMATIC S7 "System Function Calls" SFC are used in the SIMATIC-CPU for data set
access with SFC 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:
FM 458 with "virtual
connections"
1. Establish the coupling:
2. Define the send and receive data sets:
Application Module FM 458 - User Manual
6DD1904-0AE0 Edition 12.2001
various "data sets" (or "telegrams").
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!
114688 bytes / (5 * 240 bytes) = 95.5733
Configure a central communications block @CPB (from the
"SpezKomm" block family) to initialize and monitor the data set
coupling.
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:
Configuring
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