Rockwell Automation 1788 NetLinx Media Checker Users Manual - Manual (Page 17)

The Test Function (TEST) 17
1788-UM002A-US-P – April 2000
Table 8. DeviceNet Test Failures (with Cable ID) (cont.)
1
Display Failure Description
Short to the shield. “SHORT” is blinking. There is a resistive fault between S and L.
It could be a short or a slightly higher resistance. Check the
connectors first; then look for a crushed spot on the cable. You
can use an ohmmeter to measure the short’s resistance, then
use the information given under “Calculating the Distance to a
Short” on page 32 to determine the distance to the short.
Three wires are shorted. “SHORT”, “FAULT”, and “OPEN” are blinking.
2
The L and –
wires are shorted to the shield (S). Use the measured resistance
(6
Ω
in this case) and the information given under “Calculating
the Distance to a Short” on page 32 to determine the distance to
the short.
1. The MediaChecker might not be able to map some situations with four or five wires miswired. In all cases, the MediaChecker indicates
a fault and gives a partial description of the problem, but might not identify all of the wiring errors.
2. Because some measurements are not possible on faulted cables, the MediaChecker might report the H wire as open when it is not
actually open.