Chapter 2. Installation61200.129L1-1 TSU 120 User Manual 3 1POWER UP TESTING AND INITIALIZATIONWhen shipped from the factory, the TSU 120 is set tofactory default conditions. At the first application ofpower, the unit automatically executes a memory selftest. A full self test can be run from the front panel,and a pass code and unit ID may be set using the UTILmenu.Self TestUpon a power-up, the LCD displays Memory TestNow Testing and the Test LEDs are illuminated.When the self test is completed with no failuresdetected, the OK LED lights up and the LCD momen-tarily displays All Tests Passed. If a failure is detecteda list of failures is displayed in the LCD window. Thefull self test procedure (invoked from the front panelor T-Watch) consists of the following steps:1. Board level tests. Each of the TSU 120 boardcontains an on-board processor which executes aseries of tests checking the circuitry on the board.a. RAM tests; EPROM checksumb. DS0 map testsc. On-board data path. Sending a known testpattern through an on-board loop.2. Unit level tests.a. Front panel LED verificationb. Phase locked loop verificationc. Board-to-board interface test. A test pattern issent from the controller through a loopback onall other boards and checked on the controller.This verifies the data path, clocks, and controlsignals.
