Word (Transmit). The Bus Controller sends one command word with a Sub-address of 0 or 31 signifying a Mode Code type command. The Remote Terminal responds with a Status word immediately followed by a single Data word. Mode Command With Data Word (Receive). The Bus Controller sends one command word with a Sub-address of 0 or 31 signifying a Mode Code type command immediately followed by a single data word. The Remote Terminal responds with a Status word. MIL-STD-1553B also introduced the concept of optional broadcast transfers, in which data is sent to all RTs that implement the option, but to which no RTs respond, as this would cause conflicts on the bus. These can be used where the same data is sent to multiple RTs, to reduce the number of transactions and thus reduce the loading on the data bus. However, the lack of explicit responses by the RTs receiving these broadcasts means that these transfers cannot be automatically re-tried in the event of an error in the transaction. Four types of broadcast transactions are allowed between the BC and all capable RTs: Controller to RT(s) Transfer. The Bus Controller sends one receive command word with a Terminal address of 31 signifying a broadcast type command, immediately followed by 0 to 32 data words. All Remote Terminals that implement broadcasts will accept the data but no Remote Terminals will respond. RT to RT(s) Transfers. The Bus Controller sends out one receive command word with a Terminal address of 31 signifying a broadcast type command, immediately followed by one transmit command. The transmitting Remote Terminal sends a Status word immediately followed by 1 to 32 data words. All Remote Terminals that implement broadcasts will accept the data but no Remote Terminals will respond. Mode Command Without Data Word (Broadcast). The Bus Controller sends one command word with a Terminal address of 31 signifying a broadcast type command and a sub-address of 0 or 31 signifying a Mode Code type command. No Remote Terminals will respond. Mode Command With Data Word (Broadcast). The Bus Controller sends one command word with a Terminal address of 31 signifying a broadcast type command and a sub-address of 0 or 31 signifying a Mode Code type command, immediately followed by one Data word. No Remote Terminals will respond. The Command Word is built as follows. The first 5 bits are the Remote Terminal address (0–31).