Siemens SIMATIC S5-115U, User Manual

Page: 441 / 676

S5-115U Manual Communications Capabilities
12.1.2 Page Frame Addressing
Modules that can be programmed and modules to which parameters can be assigned (CPs and IPs)
process complex jobs in the SIMATIC S5 system. These modules have a one-kilobyte dual port RAM
for data exchange with the PLC. In the CPU, this interface memory is assigned an address area that
can be addressed linearly or via a page frame.
1
For linear addressing, each interface needs a one-kilobyte area in user memory. In order to
prevent a loss of capacity when several CPs are used, all CPs and some intelligent I/Os are
addressed via a page frame on the S5-115U. In addition to the memory area F400
H
to F7FF
H
for the
page frame, only one memory location is needed in the internal register to specify an interface
number (address FEFF
H
) between 0 and 255.
The same numbers are set on the module. This procedure determines which interface is addressed
through the page frame. If a module has two interfaces, they are numbered in ascending order.
Data handling blocks are used for data exchange (see Subsection 11.1.3). They must be called by
the control program. The essential information for a particular job is entered in the parameter list
of the handling block.
12.2 SINEC L1 Local Area Network
SINEC L1 is a communications system that networks SIMATIC S5 programmable controllers of the
U range. It works according to the master-slave principle:
• The master is a separate PLC that handles the entire coordination and monitoring of data
traffic in the local area network.
The master PLC must have a CP 530 communications processor.
• A slave can be any PLC.
"Data handling blocks" which support communications with the CP 530 are integrated in the
central processing units of the S5-115U (see Section 11.1.3).
1 A page frame is a specific area of the user memory.
EWA 4NEB 811 6130-02b
12-7