Condor Engineering 1553 interface boards can run on either an internal bus or an external bus. When run on the internal bus, all 1553 transactions occur on the board. No 1553 data is actually transmitted or received. When run on the external bus, all transactions occur on the external 1553 bus. This means when the board is set for internal bus, it does not transmit or receive any 1553 signals. The default setting after initializing the board is internal bus. If you want to connect to an external 1553 bus, you must configure for external operation. Do this by calling BusTools_SetInternalBus. The calling options are:
status = BusTools_SetInternalBus(cardnum, EXTERNAL_BUS); //Run on external busor
status = BusTools_SetInternalBus(cardnum.INTERNAL_BUS); // Run on internal bus.Once you set the board for external bus, you start sending and receiving 1553 data.