Cable tests
Page 152 OmniTrax Product Guide
Cable-set continuity test (open ended perimeter)
1. At the processor, disconnect the sensor cables that are being tested (TXA and RXA OR TXB
and RXB).
2. Using a digital multimeter, measure the resistance between the center pin and shield on each
connector.
• A resistance of 130 k
± 5% confirms the connection.
• Infinite resistance means the cables are not properly connected, terminated, or are
incorrectly labeled. Re-label or repair as required.
• A zero reading indicates a short. Check the meter clips and repair as required.
The surface test
A surface test can identify potential system problems while the cables and connections are readily
accessible. A surface test should be conducted for all installations, but is particularly important for
installations in which the cables pass through more than one burial media. Once the connections
are sealed and the cables are buried, detection problems are much more difficult to resolve.
Before applying power, verify the sensor cable connections and the wiring connections to the
processor. Once the connections are verified, power up and test the system before burying the
sensor cables, or sealing the slots.
1. Apply power to the processor.
2. Connect the UCM to the processor.
3. Perform a centerline cable walk, while running a plot file in the UCM.
Figure 136: OC2 cable-set continuity test
Note Refer to the UCM help file, and Chapter 7 for additional details about
the following procedure.
The surface test does not require the alarm data wiring (network or
local) and the power source can be a 12 VDC battery.
PEAK
HOLD
ON OFF
DC
AC
TEMP C
2000 mA
200 mA
20 mA
2 mA
200 mV
200¦
2
20
200
1000 DC
750 AC
20M
2000k
200k
20k
2k
200 nS
mA
V
*C
S
¦
mA *C
V ¦
S
TXA
RXA
TXA
RXA
130
multimeter
measure center-pin to shield (reading = 130 k ±5%)
terminator
disconnected cable set
standalone
decouplers
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