MIL-STD-1553 Channel and Bus Function Specifications Explained

Updated Feb 15, 2019

Reported In


  • PXI MIL-STD-1553 Interface Module

Issue Details

What do the Number of MIL Channels and Bus Function specifications mean with regard to the PXI MIL-STD-1553 interface modules ?


MIL-STD-1553 is a dual redundant bus, meaning that each channel has a BUS A and a BUS B. These buses cannot be treated as separate channels, but if a message is transmitted on Channel 0, BUS A and fails, the message can be re-transmitted on Channel 0, BUS B. Each channel will have a BUS A and a BUS B, but you can only transmit or receive on one bus at a time.

The Bus Function specification mainly reflects whether or not the module can act as a single 1553 component or multiple 1553 components at one time. The 1553 components are a Bus Controller (BC), a Bus Monitor (BM), and a Remote Terminal (RT). A Single-Function module can only act as one component on a single channel. A Multi-Function module can act as any combination of the three, meaning you can simulate a BC, BM, and up to 32 RTs all on a single channel. There are additional differences that can be found on Table 6.3 of the User Manual. (Note: Multi-Function modules sold by National Instruments are actually Multifunction with Parametrics, as detailed in the manual.)