9-1
DP/PA Link and Y Link Bus Couplings
A5E00193841-011
Diagnostics Using LEDs
Overview of contents
This chapter describes the meanings of the LED displays on the IM 157, the
DP/PA coupler and the Y coupler. If the LEDs indicate an error condition, the
possible causes and suggested corrective measures are provided in tables.
Section Topic Page
9.1 LED displays of the IM 157 9-2
9.2 LED displays of the DP/PA coupler 9-5
9.3 LED displays of the Y coupler 9-6
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