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Troubleshooting X-Talk Failure
Capacitive coupling is increased when the physical distance between two
conductors is very close over a long distance.
Things that increase coupling:
Insulation integrity is reduced by nicked or cut insulation. Exposed
conductors can have increased capacitance to other conduc-
tors.Especially earth. If shielded wire is used, it is very important to
maintain the integrity of the insulation and to prevent the shield from
contacting earth. Keep the drain wire insulated as close to the termi-
nation as possible.
Single conductor wire, such as THHN, coupling to other THHN con-
ductors and to conduit more than the coupling to the other conductor
in the pair. THHN or similar single conductor wires are not recom-
mended for IDNet or MAPNET, except for IDNet+ card used with
4100U, 4100ES, and 4010ES.
Inductive Coupling is caused by the electromagnetic field of a signal
interfering with the electrical signal on an adjacent conductor. Inductive
coupling interference is worse when a current changes rapidly in amplitude.
Signals that cause interference from inductive coupling include Strobes and
Voice NACs. Shielded wiring can eliminate inductive coupling by breaking the
path of the inductive field.
Resistive Coupling is usually caused by exposed conductors. Moisture and
contamination can create a conductive path to other conductors. Often, this
will be shown with the earth fault test. Nicked or cut insulation, combined with
moisture and contamination can result in electrical paths between wires.
Test IDC/zone
Test conventional Initiating Device Circuits with this menu selection. At the
top level menu, navigate to [Test IDC/zone] with the up/down arrow keys and
press ENT to select the IDC test.
If the leads are not connected to IDC wiring, the display should show the
results of the test as "Open", indicating that there is no End of Line Resistor
between the red and black leads.
