Mode of operation

Coupling to FM 458-1 DP

The EXM 448 is connected directly to the FM 458-1 DP basic module via the internal bus. Only the power supply is obtained from the backplane bus of the SIMATIC rack, data transfer is not handled here. Access to the I/O is via configurable function blocks.

Configuration

Configuration instead of programming with CFC

The FM 458-1 DP is configured using the well-known software tools STEP 7 and CFC (Continuous Function Chart) which are also used to program the SIMATIC S7-400.

CFC is an intuitive Windows-based program that is easy to learn. The CFC has been expanded to include the function blocks and the optimized operating system using the D7-SYS add-on software package.

For further information on D7-SYS, refer to "SIMATIC Software/Engineering Tools".

DP master programming with COM PROFIBUS

If an EXM 448 is to be used as PROFIBUS DP master, the associated bus parameters must be calculated using the COM PROFIBUS PC program and downloaded to the EXM 448. Parameterization with COM PROFIBUS is not required when using as DP slave.

The bus parameters can be downloaded to the EXM 448 expansion module over the following interfaces:

• With the PROFIBUS DP connection in the PC, directly over the PROFIBUS cable, e.g. with the PROFIBUS PC cards CP 5611 (PCI), CP 5411 (ISA) or CP 5511 (PCMCIA).
• Over the MPI interface of a PC or PG; transmission rate 187.5 Kbit/s.
• With the "SS52load" program over the RS 232 interface of the EXM 448;
  "SS52load" is included in COM PROFIBUS from V3.1 onwards.