The T3 data display area includes the real time clock and the GPS and battery indicators (at the top), the measurement data (in the middle), the instrument settings summary (at the left side), the submenu key labels (at the right side), and the main menu key labels (at the bottom). The submenu key labels vary in relation to the main menu key selection.

The instrument settings summary shows the status of the T3 configuration, including: Test Mode, Line Coding, Clock Source, Receive Input, Framing Mode, Error Insert, Pattern, Payload Type, Loopback Type, LBO Select, and Measure.

The upper part of the measurement data display has an area that is highlighted in yellow, which reports historical and current pass/fail conditions for parameters relating to Rx (Receive), DS3, DS1, and Insert testing. See Figure: T3 Parameters for Historical and Pass/Fail Conditions for an example of this display when testing DS1 from DS3. For Rx, the parameters are Signal, Frame Sync, and Pattern Sync. For DS3, the parameters are Alarms, Errors, and B3ZS. For DS1, the parameters are Alarms, Errors, and B8ZS. For Insert, the parameters are Alarm ON, Error ON, and Loop ON.

The columns of historical data (for Rx, DS3, and DS1) are labeled with an H. The adjacent columns display current (present time) conditions. The B3ZS indicator for DS3 displays only the current condition (no historical data). The H indicators turn red when an error has occurred previous to the current pass/fail condition. These history error indications are cleared by pressing the Clear History submenu key in the Measurements menu. The Insert column indicators display ON/OFF status for Alarm, Error, and Loop testing. Two views are presented for this status window: DS3 with DS3 full payload, and DS3 with DS1 payload. The B8ZS light is OFF in this configuration (as shown in Figure: BTS and MSC Configuration) because the DS3 signal does not use B8ZS encoding. Compare this with Figure: T1 Display Screen, which is for DS1 only.

The remainder of the measurement display is used for set ups, configurations, and measurement display, which changes with the selected function.

The T3 main menu key labels are: Configuration, Pattern/Loop, Error/Alarm, Measurements, and Start/Stop.