EBR-1553 is a communication standard based on MIL-STD-1553, but specified to operate at a higher data rate of 10 Mb/s. It operates over a hub (star) topology, with the Bus Controller (BC) node at the center of the hub and RTs located on the spokes. The EBR-1553 physical layer calls for point-to-point connections using RS-485 transceivers.
EBR-1553 is deployed on weapon systems, including the “Small Diameter Bomb” (SDB).
Sital’s products includes a 1553 EBR IP core that provides:
- DDC’s Enhanced Mini-ACE register/memory architecture.
- BC, RT and Monitor operation.
- A hub that can be instantiated to provide any number of ports up to and including 32.
The core can be supplied with software API/library/drivers for Windows, VxWorks and Linux.
Sital also offers EBR-1553 boards in a variety of form factors, including PCI Express, PCI, PMC, VME, PC/104, Compact PCI, and USB.
Two versions of boards are available – standard interface boards and a tester boards.
Both versions of boards provide BC, RT and Monitor operation, including 4-port EBR-1553 hubs.
In addition, the tester versions of the boards provide error-injection capabilities and also include the COMposer Windows GUI software.
The Challenges with EBR1553 interface and Sital’s solutions for them:
EBR1553 interface solutions provided on the market suffer from several issues:
- There is no formal validation testing for EBR1553 as there is for a standard MIL-STD-1553.
- Some vendors implement EBR1553 Link mode with manually controlled Multiplexer for the BC HUB.
- Some EBR1553 testers can only operate at bus wire’s length of a few meters only.
Sital Technology provides an EBR1553 components and testers that solve that issues:
- Missing Validation Criteria: An LRU equipped with MIL-STD-1553 is required to pass RT Validation before first air-born. This assures seamless interoperability between LRUs from different vendors. EBR1553 lacks the RT Validation, or any other type of validation. This gap created at least two dialects of EBR1553, the Lockheed Martine dialect, and the Boeing dialect. Those dialects are somewhat different, such that interoperability between two LRUs with different dialect might fail communication.
- Sital Technology’s EBR1553 IP cores and Testers support both dialects.
- Sital Technology’s EBR1553 IP cores and Testers pass through a rigid set of validation tests that are extracted from the MIL-STD-1553 RT/MT/BC Validation test set.
- EBR1553 Link mode: In EBR1553 BC HUB Link mode, each line/link serves messages for different RT address, for example link #3 would carry messages to RT3, however in link mode RT address in the command is changed to 0. In Sital’s EBR1553 that is exactly what happens, transparent to the programmer. The programmer adds a BC message to RT3, and Sital’s EBR1553 IP routes it through line 3, but also changes the RT address of the command to 0. Most other EBR1553 solutions out there do not change the RT address automatically, so their BC has to load the frame with command to RT address 0, and specify somehow, awkward, to route this message through link 3. But what happens if the next message is for RT2, can it do all these routing back to back…??? Probably not
- Sital’s EBR1553 does all these conversions automatically and uses the very same Enhanced Mini Ace API functions as for MIL-STD-1553. Fully transparent.
- Line/Link maximum length: EBR1553 runs on RS485 physical layer instead of the floating MIL-STD-1553 standard. EBR1553 is point to point between the BC HUB and each of the RTs. Both ends are terminated by 120 Ohm. It so happens that in some cases and for some vendors, their EBR1553 transmitters fail to properly shape their 10Mbps signaling, and communication fails. For short bus wires lengths, it still works, but as the length extends, such as in a bigger weapon system on bigger aircraft, communication fails. Typically, we have seen comm fail at wires length longer than 12 meters. However, it must be considered that failures at 12 meters exposes very low SNR at 10, 8 and 6 meters.
- In Sital Technology we conducted a thorough analysis into their failure, understood the reason for it, and composed a robust EBR1553 transmitter receiver that performs well, with excellent SNR up to 50 meters of RS485 line/link.
- Our EBR1553 IPs are dispatched in multiple applications flying and testing since 2015.