Chapter 3. Operation3-4 TSU 120 User Manual 61202129L1-1DSU/DSX StatusThe DSU/DSX status LEDs display the operational conditionof the Nx56/64 and DSX-1 parts included in the TSU 120. Italso reflects the status of the DBU in the TSU 120e.Module StatusThe module status LEDs display the operational condition ofports installed in the option slots.OK (GREEN ) Indicates the operation is in the normal modeand no errors have been detected.TEST(YELLOW )Indicates that one of the interfaces is operatingin a test mode. This includes a self-test or a testloopback. When lighted, this LED also indicatesthat normal data flow is not occurring in at leastone of the module ports.A LARM ( RED ) Indicates an alarm condition has been detected.When the alarm condition is no longer valid, theOK LED activates (turns on). To view an alarmcondition, select the active alarm menu item orselect Alarm by pressing Shift+8. If the alarmconditions have been corrected, the alarmwhich caused the activation of the Alarm LEDcan be viewed under the Unit History Menu.OK ( GREEN ) Indicates the operation is in the normal modeand no errors have been detected.TEST( YELLOW)Indicates that one of the interfaces is operatingin a test mode. This includes a self-test or a testloopback. When lighted, this LED also indicatesthat normal data flow is not occurring in at leastone of the module ports.
