Chapter 4 Tutorial
Local Loopback Test
4-3
TC8612 Rev 1.1 User Manual
4.4
Local Loopback Test
With the front panel SW1 (LOCLB) in the On (Down) position and a valid dry
contact electrical signal present at the RJ-45, the incoming dry contact detector
signal on pin 1 & 2 of Port 1 will be looped back to pin 1 & 2 of Port 3. The
loopback is formed inside the TC8612 after the input signal is converted to the TTL
level. The purpose of this test is to verify the input and output wiring connections,
signal input receiver and signal output driver.
1.
The "DET," and "RLY" LEDs on the front panel will flash for that particular
channel being tested and the "ALM" alarm LED will flash to indicate that the
unit is in diagnostic (local loopback) mode.
2.
The "SYNC" and "LOS" LEDs will be blinking since there is no T1/E1 link
established for this test.
3.
Check that the volt meter is indicating connection integrity.
4.
Upon successful completion of this test, please return dip switch SW2
(LOCLB) to the Up (Off) position and proceed to the Remote Loopback Test.
