- There are two AG-T1s in the system. The first AG-T1 board is the MVIP master which drives the MVIP clock from the PSTN network connection. The second AG-T1 board drives the SEC8K signal from the PSTN network connection in case the first AG-T1 board loses its network connection.
- If the first AG-T1 board, which is the MVIP master, loses its network connection, software must intervene to choose SEC8K as its clock source for the first AG-T1 board. The second AG-T1 board synchronizes off the MVIP clock being driven by the first AG-T1 board.
- This example:
- Configures the board clock of the first AG-T1 to synchronize to the PSTN clocks and become the MVIP master.
- Configures the board clock of the second AG-T1 to synchronize off the MVIP clock.
- Configures the second AG-T1 to drive the SEC8K signal on the MVIP bus from its PSTN connection.
- Explains what to do if the first AG-T1 loses its PSTN connection. Configure the board clock of the first AG-T1 to synchronize to the SEC8K signal on the MVIP bus (being driven by the second AG-T1 from its PSTN connection).
- For purposes of this example, the hardware is 2 AG-T1 boards with independent connections to the PSTN.
Program
- Configure the board clock of the first AG-T1 to synchronize to the PSTN clocks and become the MVIP clock master:
SWI_CLOCK_ARGS boardclock;
/* Make first AG-T1 sync off the PSTN digital trunk 1 */
boardclock.size = sizeof(SWI_CLOCK_ARGS);
boardclock.clocktype = MVIP95_STD_CLOCKING;
boardclock.clocksource = MVIP95_SOURCE_NETWORK;
boardclock.network = 1;
swiConfigBoardClock(firstt1, &boardclock);
- Configure the board clock of the second AG-T1 to synchronize off the MVIP clock:
/* Make second AG-T1 sync off MVIP bus clock being driven by first AG-T1 */
boardclock.size = sizeof(SWI_CLOCK_ARGS);
boardclock.clocktype = MVIP95_STD_CLOCKING;
boardclock.clocksource = MVIP95_SOURCE_MVIP;
boardclock.network = 0;
swiConfigBoardClock(secondt1, &boardclock);
- Configure the second AG-T1 to drive the SEC8K signal on the MVIP bus from its PSTN connection:
/* Make second AG-T1's network 1 provide the source of the Sec8K signal */
swiConfigSec8KClock(secondt1, MVIP95_SOURCE_NETWORK, 1);
- This is the state of the clocks after configuring the two AG-T1 boards and the SEC8K signal on the MVIP bus.
Figure 12. Clocks After Configuring the AG-T1 Boards and SEC8K Signal
- If the first AG-T1 board loses its PSTN connection, configure its board clock to synchronize to the SEC8K signal on the MVIP bus (being driven by the second AG-T1 board from its PSTN connection).
/* Make AG-T1 sync off SEC8K */
boardclock.size = sizeof(SWI_CLOCK_ARGS);
boardclock.clocktype = MVIP95_STD_CLOCKING;
boardclock.clocksource = MVIP95_SOURCE_SEC8K;
swiConfigBoardClock(firstt1, &boardclock);
- This is the state of the clocks after the first AG-T1 board has been configured to synchronize to the SEC8K signal on the MVIP bus.
Figure 13. State of the Clocks
(Page 3 of 4 in this chapter)