Installation
150-512-100-03, Revision 03
14
September 25, 1998
HRU-512 List 1
I
NSTALLATION
T
EST
Perform the following procedure to test the HRU-512 List 1.
1
Press the loopback button (see Figure 2 for the location of this button for
at least five seconds.
Verify that the LB NET LED lights green, indicating that the
HRU-512 List 1 is in a digital (NREM) loopback state. If possible, verify
that the HLU front panel displays NREM.
2
Have the CO transmit a T1 test signal to the HLU.
Measure the return (loop) signal to verify it is error free. If the signal is
not error free, remove the HRU-512 List 1 from loopback by pressing the
loopback button for five seconds. The LB NET LED should be off.
3
Have the CO send the HLU 4-in 8 in-band loop-up (NLOC) for five
seconds.
If possible, verify that the HLU front panel displays NLOC.
4
Repeat step 2.
If the test passes, the problem is in the cable pair or in the
HRU-512 List 1. If the test fails, the problem is at the CO.
5
Check that the proper ports are in use for the HDSL and DS1 pair by
using an ohm-meter to verify that the HDSL port has a 390 k
Ω
transmit
to receive resistive signature and that the DS1 ports which have a 15
Ω
transmit to receive resistive signature.
Measure the return (loop) signal to verify it is error free.
6
If using an external NID, set the I-CPE switch (located on the back panel
of the HRU-512 List 1; see
) to 60 mA and verify the
NDI is under power. Check that the voltage across the front panel test
points (60 mA MON) measure between 55 mV and 65 mV.
7
Enable the sealing current option (JP2 connected) if required. Use a
milli-amp meter to verify transmit or receive current in either HDSL pair.
