Siemens SIMATIC S7-400 Hardware And Installation Manual page 281

I
Instance Data With the S7-400, each call of a function block in the STEP 7 user
Block
program is assigned a data block which is generated automatically. In
the instance data block, the values of the input, output and in/out
parameters as well as the local block data are stored.
Interface,
Multipoint
Interface Submodules which provide the automation computer with additional
Submodules interfaces, such as VGA, COM, PROFIBUS DP, etc.
Interrupt The operating system of the S7-400 CPU has 10 different priority
classes which control the processing of the user program. These
priority classes include interrupts, such as hardware interrupts. When
an interrupt occurs, the relevant organization block is called
automatically by the operating system in which the user can program
the required reaction to the interrupt (for example, in a function block
(FB)).
Interrupt,
Cyclic
Interrupt,
Diagnostic
Interrupt,
Hardware
Interrupt,
Time-Delay
Interrupt,
Time-Of-Day
ISA Bus The ISA bus is the standard bus in the AT-compatible PC. It is looped
through the M7-400 module assembly via the 120-pin expansion
sockets and plugs of the individual M7-400 modules.
Isolated In the case of isolated I/O modules, the reference potentials of the
control and load circuits are galvanically isolated from each other, for
example, by optocouplers, relay contacts, or transformers. The I/O
circuits can be connected to a common potential.
S7-400 and M7-400 Programmable Controllers, Installation Manual
C79000-G7076-C424-01
www.gkbpx.com
Multipoint Interface
Cyclic Interrupt
Diagnostic Interrupt
Hardware Interrupt
Time-Delay Interrupt
Time-Of-Day Interrupt
Glossary
Glossary-7