Your question about Siemens S30810-Q2114-X MBU

The MBU (message buffer unit) for the Hicom 300/300E, controls the exchange of messages between the central processor (SWU), the call processing periphery (LTGs) and the central switching network (CSN).

Three HDLC links are used for this purpose. Two of the HDLC links serve four each of the total of eight LTGs, the third link serves the central switching network (CSN).

The MBU board includes all the functions of the MD board (message distributor). The MBU assigns the HDLC connections itself.

The front panel of the board contains a 7-segment display, 2 LEDs (RUN 1+2), 2 keys (Reset, Monitor) and one V.24 interface.