LINKUP 5294 WITH DL5294 FIRMWARE
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9. Diagnostics
The first two section of this chapter review the on-line and off-line diagnostic capabilities of the LinkUp
5294. The third section will help you find and solve common problems you may encounter when you use
the LinkUp 5294.
9.1 On-Line Diagnostics
The on-line diagnostic capabilities of the LinkUp 5294 include:
• Watchdog Timer
• Error Code displays
• Communication Line Status Indicators
• Remote Interface Signal Display
• Sync Port Address Trace
• Async Port Trace
• Sync Port Trace (deluxe model only)
The Watchdog Timer enables the LinkUp 5294 to monitor its own program execution continuously in
the background of daily operations, assuring you of its overall system integrity. If a program execution
fails, the LinkUp 5294 alerts you with an Error Code display. Error Code displays and Communication
Line Status indicators are the LinkUp 5294 front panel LEDs. Each one of these will be discussed in the
next two sections.
9.1.1 F
RONT
-P
ANEL
E
RROR
C
ODES
If a program-detectable error occurs, all channel status indicators on the front panel are turned off and
a two-level error code is displayed by the two-digit channel display. The two error codes are flashed
alternately. Table 9-1 describes the error code assignments currently implemented in the LinkUp 5294.
When an error code is displayed, pressing the RESET button will clear the error code and cause channel
status display to resume. However, if more than one error has occurred, pressing RESET will clear the
most recent error code and display the previous one. Preceding error codes can then be viewed by
pressing RESET repeatedly until the channel status indicators resume their normal operation. This
marks the end of accumulated errors. Once error codes are cleared, they cannot be redisplayed on the
front panel.
9.1.2 F
RONT
-P
ANEL
S
TATUS
I
NDICATORS
The LinkUp 5294 front panel lets you monitor a total of 13 different communication line status
indicators for any port. If a problem occurs on one of the communication lines established on one of the
LinkUp 5294 ports, you can troubleshoot that problem by scrolling to the affected port number (using
the CHannel SELect control button) and then examining the displayed status indicators. If the
appropriate status indicators are not lit, you will be able to target the line’s problem by trial and error.
Check the lights on the LinkUp’s front panel when you have a communication-line problem. By
comparing which signals are lit to which signals should be lit, you may be able to isolate the problem.
For your reference, Table 9-2 lists the front-panel signals, their definitions, and a brief explanation of
when each should be lit.