Glossary - Siemens SIMATIC S7-300 Hardware And Installation Manual

Glossary

Terminating resistor
The terminating resistor is used to avoid reflections on data links.
Address
An address represents the ID for a specific address or address range. Example:
Input I12.1; Memory bit word MW25; Data block DB3.
Accumulator
The --> CPU uses the accumulator registers as intermediate memory for load,
transfer, comparison, calculation and conversion operations.
Interrupt
The CPU's --> operating system knows 10 different priority classes for controlling
user program execution. These priority classes include interrupts, such as process
interrupts.When an interrupt is triggered, the operating system automatically calls
an assigned OB. In this OB the user can program the desired response (for
example in an FB).
Interrupt, vendor-specific
A vendor-specific interrupt can be generated by a DPV1 slave. It causes OB 57 to
be called on the DPV1 master.
Detailed information on OB 57 can be found in the Reference Manual "System
Software for S7-300/400: System and Standard Functions"
Interrupt, update
An update interrupt can be generated by a DPV1 slave and causes OB 56 to be
called on the DPV1 master. For detailed information on OB 56, see the Reference
Manual "System software for S7-300/400: System and Standard Functions"
S7-300 Programmable Controller Hardware and Installation
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