CTP Systems CTPhone 1900, Руководство по применению

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DOC00101-01 5-3
Diagnostics and Troubleshooting
Polarity
Check that transmit and receive pairs are consistent between the
CTPhone Controller and base stations throughout the system. Sometimes
switching pairs at the base station will solve a problem quickly.
Continuity
You can use an installer’s test set at individual MDF/IDF locations to check
analog line continuity throughout a system.
Check for any bridge taps on the base station transmit/receive cables.
Remove them, if found. Check all punch downs and cable connections.
CTPhone Controller/Base Station Communication
One method of testing whether system problems are due to a communica-
tion problem between the CTPhone Controller and base station is to per-
form a software version query of the base station from the CTPhone
Manager. If you receive no response to the query, check the cables
between the CTPhone Controller and base stations, the RS-232-C cable
between the PC and CTPhone Controller, and that the base stations and
CTPhone Controller are running normally.
Distance Limitations
The allowed distances between CTPhone Controller and base station
(whether using line power from the CTPhone Controller or a local power
supply) may be exceeded during an installation. You can use the following
test to measure DC resistance between the CTPhone Controller and base
stations, which will determine if this is the case.
To perform this test the following tools are needed:
• Digital multimeter that has resistance measuring capability with a reso-
lution of at least units of ohms and a basic accuracy of better than 1%
• RJ-11 female to female line adapter
Table 5-A lists the maximum DC resistance allowed for line or local power.
Table 5-A. DC Resistance on Base Station/Controller Cables
Input Power Wire Gauge
Maximum DC
Resistance Allowed
Line 22, 24, or mixed 22/24 98 ohms
Local 22 108 ohms
24 171 ohms