Chapter 3. Operation61202156L2 TDU 120e User Manual 3-9LEDsNetwork Status LEDsThe network status LEDs display the operational condi-tion of the network interface located on the controllerboard in the unit.LEDDisplayColor Indicates that...OK Green The operation is in the normal mode and noerrors have been detected.Test Yellow The network interface is operating in a testmode. This includes a self-test or a testloopback. When lighted, this LED alsoindicates that normal data flow is notoccurring on the network interface.Error Red An error has occurred, such as a BPV, OOF,or CRC.Alarm Red An alarm condition has been detected. Anyalarm condition will activate the alarm relayfor the external alarm device. When thealarm condition is no longer valid, the OKLED activates (turns on). To view an alarmcondition, select the active alarm menu item.If the alarm conditions have been corrected, the alarm which caused theactivation of the Alarm LED can be viewed under theU NIT HISTORYmenu.
