Siemens SIMATIC S7-300 Reference Manual page 551

Default setting
The default setting is a sensible basic setting that is used whenever no other
value is used.
Destruction limit
Limit of permitted input voltage / input current.
If this limit is exceeded, the measuring accuracy may deteriorate. If the destruc-
tion limit is exceeded by a vast amount, this may destroy the internal measuring
circuit.
Diagnostic buffer
The diagnostic buffer is a buffered memory area in the CPU which stores the
diagnostics events in the order in which they occurred.
For troubleshooting, the user can read out the exact error cause in STEP 7
(PLC –> Module State) from the diagnostic buffer.
Diagnostic data
All the diagnostics events that occurred are collected in the CPU and entered in
the → Diagnostic buffer. If there is an error OB, it is started.
Diagnostic Interrupt
Modules with diagnostics capability report system errors by means of diagnostic
interrupts to the → CPU. The operating system of the CPU calls OB 82 in the
course of a diagnostic interrupt.
Diagnostics
Generic term for → System diagnostics, process error diagnosis and user-de-
fined diagnostics.
Direct access
A direct access is the direct accessing of the CPU by means of the → Backplane
bus to modules while avoiding the → Process image.
Encoder absolute
An encoder absolute determines the path traveled during position detection by
reading a numerical value. In the case of encoders absolute with a serial inter-
face (SSI), path information is transferred synchronously and serially according
to the SSI protocol (synchronous serial interface).
Programmable Logic Controllers S7-300 Module Data
A5E00105505-03
Glossary
Glossary-3