II - DCE FEL ČVUT v Praze

D
Diagnostic
interrupt
Diagnostic buffer
Diagnostics
Distributed
I/O device
DP address
DP master
I/O Modules with Intrinsically-Safe Signals
C79000-G7076-C152-04
Modules with a diagnostics capability report any system faults or errors they
have identified to the CPU by means of diagnostic interrupts.
In SIMATIC S7/M7: When a fault (e.g. a wire break) is detected or when it
disappears again, the module outputs a diagnostic interrupt, providing
diagnostics have been enabled for it. The CPU stops processing the user
program and any events with lower priority classes, and processes the
diagnostic interrupt block instead (OB 82).
In SIMATIC S5: The diagnostic interrupt is simulated as part of the
device-specific diagnostics. You can detect faults (e.g. a wire break) by
cyclically interrogating the diagnostic bits of this diagnostics.
The diagnostic buffer is a backed-up memory area in the CPU where
diagnostic events are stored in the order they occur.
Detection, localization, classification, indication and other forms of
evaluation of errors, faults, malfunctions and interrupts.
’Diagnostics’ includes monitoring functions which are activated
automatically whenever the system is operational. The system availability is
increased as a result, and commissioning and down times are reduced.
The ET 200 incorporates various diagnostic functions, from information
about the DP slave which has reported the diagnostics to monitoring of
individual channels.
An input/output unit which is installed not in the central processing unit, but
at a decentralized location remote from it, e.g.:
ET 200M, ET 200B, ET 200C, ET 200U
DP/AS-I link
S5-95U with PROFIBUS-DP slave interface
Other DP slaves from Siemens or equivalent vendors
The distributed I/O devices are connected to the DP master by means of the
PROFIBUS-DP.
Each bus device must be given a DP address, to enable it to be uniquely
identified on the PROFIBUS-DP.
The DP address of the PC/PU or the handheld ET 200 is ”0”.
The DP master and the DP slaves have DP addresses between 1 and 125.
A master which complies with EN 50170, Volume 2, PROFIBUS, is
referred to as a DP master.
Glossary
Glossary-3