Major features
  - Is a multi-function MIL connection board of Jiaxun MDS3400 switchboard
- The board can plug in 4 small boards
- There is a DSP power module on the board
- Supported board types: HL loop circuit (1 line), CS magnetic crystal (2 lines), 2-wire voice
- line Y2P (2 lines), 4-wire voice line Y4P (2 lines), XH number selection (2 lines), GD shared power (only for mid-zone function, 2 lines)
- Adjustable amplifier softwareMDS3400 command and control system repair manual
- Support online software upgrade