Addressing In The Cpu User Program (Cpu Viewpoint) - Siemens SIMATIC S5 Manual

Addressing
5.2

Addressing in the CPU User Program (CPU Viewpoint)

The CPU accesses the IP 265 via the process image of the inputs (PII) and the process image of
the outputs (PIQ). The CPU addresses the IP 265 in the address space of the analog channels. The
address space is determined by the slot selected for the IP 265.
The address area of the module comprises 8 bytes of input data and 8 bytes of output data. Input
and output data are addressed via the same address space.
The reserved 8 bytes have a fixed meaning:
Output data for IP 265 is stored by the CPU user program in the process image of the outputs (PIQ):
• Control word (2 bytes)
• Input parameters of the IP 265 user program (6 bytes)
In the process image of the inputs (PII), input data is provided by the IP 265 for evaluation in the
CPU user program:
• Status word (2 bytes)
• Output parameters of the IP 265 user program (6 bytes)
Note
The control word, status word and parameters of the CPU can be addressed bit by bit,
byte by byte or word by word.
Please consider the following for addressing:
• The module may only be used in slots 0 to 7.
• The address space ranges from byte 64 to byte 127.
• For each slot, 8 bytes are reserved both in the process image of the inputs (PII) and in the
process image of the outputs (PIQ) of the CPU.
Table 5-4. Byte Addresses in the PII/PIQ (CPU Viewpoint)
Slot
Addresses
PII/PIQ
Starting address of a slot
5-4
0 1
64 to 72 to 80 to
71 79 87
2 3 4
88 to 96 to
95 103
IP 265
5 6
104 to 112 to 120 to
111 119 127
EWA 4NEB 812 6130-02a
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