Chapter 3. Operation3-2 TSU 120 User Manual 61202129L1-1LED DescriptionsCSU StatusThe CSU status LEDs display the operational condition of thenetwork interface located on the controller board in the unit.Numeric Keypad The numeric keypad contains the numbers0 through 9 which are used to activatemenu items and enter information (such asthe IP address).Shift (enteringspecial functionkeys)Enter special function keys by pressingand holding Shift before pressing the keyrepresenting the desired character.To activate a special function key ratherthan a number, press and hold Shift; thenthe button. See Operation Keys on page 3-5for a description of the function keys.If a key is pressed without using Shift, thenumbered item becomes active instead ofthe special function key.OK ( GREEN ) Indicates the operation is in the normal mode and noerrors have been detected.TEST( YELLOW)Indicates that the network interface is operating in a testmode. This includes a self-test or a test loopback. Whenlighted, this LED also indicates that normal data flow isnot occurring on the network interface.E RROR ( RED ) Indicates an error such as a BPV, OOF, or CRC.A LARM ( RED ) Indicates an alarm condition has been detected. When thealarm condition is no longer valid, the OK LED activates(turns on). To view an alarm condition, select the activealarm menu item or select A LARM by pressing Shift+8. Ifthe alarm conditions have been corrected, the alarm whichcaused the activation of the Alarm LED can be viewedunder the Unit History menu.Table 3-1. Front Panel DescriptionsName Description
