Read In Complete Print Format

In this era of multifunction solutions and system level approaches, 1553 and other military/avionics interfaces now exist as part of solutions that take an integrated approach.

Now with an incredible over 40 years under its belt, MIL-STD-1553’s longevity is remarkable. Popular as an avionics databus and for other military I/O purposes, 1553 enjoys a huge installed base. The 1553 bus continues to play a role in a wide variety of systems such as tanks, ships, missiles and satellites. The interface is particularly admired for its reliability. For more than three decades, 1553 has been a staple in flight and mission-critical systems aboard military aircraft. It’s even used on newer platforms such as the F-22 and F-35. The challenge today has become how to support the requirements of legacy interface schemes like 1553 while accommodating the performance needs of nextgeneration computing and electronic subsystems.

I/O schemes such as 1553 and ARINC 429 are still considered good for pure control applications. That said, those interfaces aren’t in the same bandwidth range as today’s modern interconnects. Several multipurpose communications protocols provide options to suit emerging needs. The question becomes one of using bridging or some other technique to get the best out of legacy military I/O schemes like 1553, while at the same time leveraging newer solutions, like using Ethernet as an I/O interconnect. Along that continuum, 10 Gbit Ethernet and Fibre Channel have jockeyed to satisfy these needs.

Meanwhile, a pair of larger trends has altered the 1553 landscape somewhat. On the one hand, a number of rugged box-level solutions have emerged that include 1553 alongside several other interface technologies. On the other hand, 1553-only boards make less sense at today’s level of integration. As a result, there are many so-called multifunction board and mezzanine products that combine 1553 with other board or box-level I/O functionality.

Avionics Simulator Example

An example of 1553 I/O being part of a larger system solution, is United Electronic Industries’ PowerDNA Cube. UEI’s PowerDNA Cube and its I/O interfaces were selected by ZedaSoft, a simulation and visualization software company, to provide the US Army’s Distributed Test Control Center (DTCC) with an AH-64D Apache simulator (Figure 1). Having last year won a contract from AI Signal Research Inc. (ASRI), ZedaSoft’s simulator integrated with UEI hardware and I/O was employed to support the US Army’s various aviation and communication system testing activities. ZedaSoft’s Reconfigurable Cockpit System (RCS) serves as the pilot’s station, while the Reconfigurable Desktop System (RDS) serves as the co-pilot/gunner station. ZedaSoft’s Experimenter Operator Station (EOS) controls system testing.

The RCS was customized to an AH- 64D realistic configuration which includes a wide variety of robust electronics including touch-screen multi-function displays, MetaVR’s five channel image generator, Simulation and Control Technologies’ control loading system, Bihrle Applied Research high fidelity flight model and a 120 degree horizontal and 60 degree vertical out-thewindow visual display. The two PowerDNA (Distributed Networked Automation) Cubes installed act as the simulator linkage I/O and avionics interfaces including MILSTD-1553. The cube is a 4- x 4.1- x 4-inch compact, rugged, Ethernet based interface with flexibility that allows the user to configure one or more cubes to match the specific I/O requirements.

MIL-STD-1553 for Space

For its part, many of Data Device Corp.’s (DDC) interesting 1553-related developments in the past 12 months have been part its space-qualified line of products. An example is DDC’s Total-Space ACE and TotalSpace RT chips. Total-Space ACE (shown) offers full 1553 BC, RT, MT, and RT/MT functionality to interface directly to a host processor, while the Total-Space RT is an RT-only terminal ideal for interfacing with systems without a host processor, such as an FPGA or simple logic. Both versions feature an extended -55 to +125 degrees C temperature range, and 300 Krads total dose and >85 MeV-cm²/mg SEE (Single Event Effects) radiation hardening required for the extreme environmental conditions encountered in mission critical space applications.

The devices feature compact, singlepackage design that includes transceivers, transformers, protocol and memory, and provides highly efficient operation requiring only 3.3V power. This simplifies PC board layout, power supply design, and minimizes board area and power consumption and dissipation. According to DDC, the TotalSpace ACE and Total-Space RT are the first fully integrated space-grade MIL-STD-1553 terminal products. The Total-Space ACE integrates MIL-STD-1553 protocol, host interface logic, memory, transceivers and transformers into a 1.63- x 1.13-. x 0.25-inch ceramic flatpack package. The co-fired ceramic package provides a very low thermal impedance between the transceivers and other chips and the bottom of the case.</p>

Integrating the transformers into the hybrid guarantees a match between the 1553 transceivers and transformers, as the transceivers are trimmed while paired with their respective transformers. These hybrids minimize PC board area, weight, and power while maximizing reliability (MTBF), all important parameters for the designers of space borne systems. In addition, DDC’s latest generation of 1553 hybrids are fully hardware and software compatible with the earlier SP’ACE and SP’ACE II hybrids. DDC has served the space industry for more than 3 decades as an approved supplier to NASA, ESA and JAXA.</p>

1553 and Intelligent I/O Approach

In keeping with its long-time strategy of an “Intelligent I/O” approach, North Atlantic Industries provides a wide variety of I/O function options on their board-level products. Its lasted example released in April was the 79G5, a single-slot, half-size, PCle board that can be configured with up to three intelligent I/O and communication function modules. The 79G5 PCle multifunction I/O and communication board is well suited for a wide range of applications with high-density I/O requirements. This includes digital and analog I/O, position control and measurement/simulation and communication interface applications. The 79G5 has been designed for environments with operating temperature ranges of 0 to 70 degrees C. Background Built-in-Test (BIT) continually checks and reports on the health of each channel.

The 79GF is built on NAI’s Custom-On-Standard-Architecture (COSA), which supports more than 40 different intelligent I/O, communication, measurement and simulation functions. These preexisting, fully-tested functions can be combined quickly and easily in an unlimited number of ways. Each I/O function has dedicated processing, unburdening the system processor from unnecessary data management overhead. Among those 40 I/O functions the communications related offerings include ARINC 429/575, CANBus, MIL-STD-1553B (Single/Dual/Quad Channel, Dual Redundant) and Serial communications.

1553 on PXI Express

Now long established as a leading form factor for instrumentation and test, PXI Express is very popular among military and aerospace system developers and test engineers. A leading force in PXI Express National Instruments last year embarked on a collaboration with avionics interface expert Astronics Ballard Technology. The collaboration agreement between Astronics Ballard Technology of Astronics and National Instruments (NI) calls for NI to will market and sell Ballard PXI avionics products through its global sales channel, which includes sales teams in over 40 countries, 700 field engineers, and over 35,000 unique customer accounts. Another division of Astronics: Astronics Test Systems established the initial collaboration with NI to provide an updated line of PXIbased test instruments.

The Astronics Ballard Technology products NI now represents include the advanced OmniBus II avionics interface cards for use with PXI Express for MIL-STD-1553, ARINC 429, and multi-protocol (Figure 2). Ballard also developed a new modern instrument driver for use with NI LabVIEW software and the NI LabVIEW Real-Time Module. The driver provides an improved tool set for intuitive and efficient development of bus configurations and applications. Ballard worked with NI to create an expansive library of MIL-STD-1553 and ARINC 429 examples that demonstrate the feature set of the Ballard interface to be used with PXI Express and reduce application development time.</p>

Ethernet and Mixed-Protocol I/O

In yet another example of merging Etherent and multiple avionics I/O flavors, AIM-USA has added Mixed Protocol Support to AIM’s Ethernet based interface family. The new product with Mixed Protocol support combines MIL-STD-1553 and ARINC429 data bus test and simulation capabilities in 1 ANET device (Figure 3). The ANET-MxAy Mixed Protocol ANET has a maximum of 2 dual redundant MILSTD-1553 streams and up to 12 ARINC429 channels. The MIL-STD-1553 section offers concurrent Bus Controller, Multiple RT Simulator (31) with a Mailbox and Chronological Monitor functions. All the ARINC429 channels are fully software programmable for Tx/Rx mode as well as Lo (12.5kBit/s) and Hi Speed (100kBit/s) operation.

According to AIM, the company originally developed the mixed protocol ANET for a unique customer requirement, but because of its generic nature and full flexibility, the mixed protocol ANET is suitable for all test, simulation and monitoring applications. Taking full advantage of the already introduced ANET hardware and software concept with flexible on-board processing capabilities, the device can even be turned into a dedicated standalone autonomous data converter from ARINC429 to MILSTD-1553 or vice versa, into a data logger and many other applications.

Standard ANET features like IRIG-B I/O, Discrete I/O, Trigger I/O and a general purpose USB2.0 port for hosting USB devices are available for the mixed protocol ANET with the Ethernet Interface supporting 10/100/1000 Ethernet links. An on board buffered Realtime Clock (RTC) is also available per default. The ANET-MxAy is offered with the standard AIM ANET housing as well as a ‘rugged’ housing variant.

Since the API interface of the mixed protocol ANET is compatible to the API of the individual MIL-STD-1553 and ARINC429 ANET inter- faces as well as to the other AIM supported form factors, a very efficient migration path exists for the customer’s application soft- ware. The common and powerful ANET features such as the on-board Python scripting, customer written C Applications and optional PBA.pro Engine ( for execution in the box) are also avail- able via the embedded LINUX based application support processor.

AIM-USA
Trevose, PA
(267) 982-2600
www.aim-online.com

Astronics Ballard Technology
Everett, WA
(425) 339-0281
www.astronics.com

BGG
Chesapeake, VA
(757) 366-9211
www.bbginc.com

Data Bus Products
Manhasset, NY
(516) 365-3946
www.databusproducts.com

Data Device Corp.
Bohemia, NY
(631) 567-5600
www.ddc-web.com

North Atlantic Industries
Bohemia, NY
(631) 567-1100
www.naii.com

United Electronic Industries
Walpole, MA
(508) 921-4600
www.ueidaq.com