61200.130L1-1 FSU User Manual 1 5Chapter 3. OperationLED DescriptionsThe FSU has seven LED indicators: TD1, RD1, TD2, RD2, TDN,RDN, and ALM/TST. These LEDs are identified as follows:TD1: Transmit Data (DTE 1)This LED is active when the FSU DTE 1 port is transmitting data.RD1: Receive Data (DTE 1)This LED is active when the FSU DTE 1 port is receiving data.TD2: Transmit Data (DTE 2)This LED is active when the FSU DTE 2 port is transmitting data.RD2: Receive Data (DTE 2)This LED is active when the FSU DTE 2 port is receiving data.TDN: Transmit Data (Network)This LED is active when the FSU Network port is transmittingdata.RDN: Receive Data (Network)This LED is active when the FSU Network port is receiving data.ALM/TST: Alarm/TestThis LED is active when an alarm condition exists or when theunit is in test mode. Alarm conditions include:DDS Alarm Conditions• Open loop on network• No frame synchronizationFrame Relay Alarm Condition• Network frame relay signaling state is down.External DSU/CSU Alarm Condition• DSR on an external DSU/CSU is false.
