The Model 941 is a Multi-Channel Data Quality Monitor (DQM) system packaged in a 10.5″ x 19″ EIA rack mountable chassis. The system supports eight PCM data streams. The unit provides information pertaining to the data stream quality as well as frame and subframe synchronization states. Channel status is displayed locally with leds located on the front panel. Decommutated data, frame and subframe status, word and frame number (with timing markers), is also provided in parallel word form on the unit rear panel.

Six counters accumulate Data Quality information. These counters are activated on command and can be simultaneously reset.

1. # of frames in Minor Frame Check or Lock (valid frames).

2. # of Minor Frames received with complemented synchronization patterns (inverted data).

3. # of frames in Minor Frame lock with unacceptable synchronization patterns (flywheel frames).

4. # of Minor Frames with a bit slip detected.

5. # of Minor Frame Lock to Search transitions (dropouts).

6. # of Minor Frames received while in Major Frame (Subframe) Lock (valid Major Frame).

All functions are controlled through either the local front panel display and keypad, or an IEEE-488 (RS232 is optional) remote control port. Virtual Instrument (VI) software is provided to allow the user to control the unit in a Windows point and click environment. The software provides a single-screen display of all statistics and status for all channels.