Siemens CPU 948 - Which Operands Are Available to the User Program

1.4 Which Operands are available to the User Program?
The CPU 948 provides the following operand areas for programming:
•• process image and I/Os
•• flags (F flags and S flags)
•• timers/counters
•• data blocks
Process image of the inputs
and outputs PII/PIQ
Characteristics Size
The user program can access the following data types
in the process image extremely quickly:
- single bits,
- bytes,
- words,
- double words
128 bytes
each for
inputs and
outputs
I/O area (P area)
Characteristics Size
The user program can access the I/O modules directly
via the S5 bus.
The following data types are possible:
- bytes,
- words.
256 bytes
each for
inputs and
outputs
Extended I/O area (O area)
Characteristics Size
The user program can access the I/O modules directly
via the S5 bus.
The following data types are possible:
- bytes,
- words.
256 bytes
each for
inputs and
outputs
Which Operands are available to the User Program?
CPU 948 Programming Guide
C79000-G8576-C848-04
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