4-5
SIMATIC PC RI25/45, Technical Description
C79000-G7076-C808-01
4.2
Status and Diagnostic Displays
The diagnostic display for SIMATIC PCs is triggered by the SafeCard and
realized in the form of LEDs and a seven-segment display which are visible
on the operator panel mounted on the front of the device (varies according to
PC). Monitoring features are thus controlled and the current status of the PC
is indicated.
The operator panel is a separate component and only connected to the
SafeCard via a cable (see Section on “Operator panel”).
Diagnostic port 80H- Output via 7-segment display:
Any write access to I/O port 80 is latched and its value indicated on the
two-digit 7-segment display. Every cold restart of the system (switch
ON/OFF) causes a detailed Power On Self-Test (POST). The POST
controlling steps are displayed as so-called POST codes on the 7-segment
display of the PC. The POST code descriptions are listed in Section 2.12,
“Diagnostic Messages” in the description of the motherboard.
The LEDs have the following meanings:
LED
OFF
GREEN
RED
Power
System OFF
System ON
––
Disk
Inactive
Active
––
Run
Watchdog inactive
Watchdog active
Watchdog executed
Temp
System OFF
Normal internal
temperature
Internal temperature beyond acceptance level or cable
towards temperature sensor unplugged or interrupted.
Overview
7-segment Display
LED Indicators
Monitoring Module