While the dramatic benefits of Moore’s law are obvious with processors and memory—faster speeds, more density—the I/O realm enjoys the constantly increasing levels of semiconductor integration too. The advent of ever more integrated chip solutions has enabled multifunction board products to emerge, enabling military system designers to blend a variety of I/O functions onto a single stand-alone card. These multifunction I/O boards are reaching across a number of form factors including PMC, XMC, AMC, PC/104 and PCI Express. Makers of such boards have had to be clever in choosing I/O technologies that are suited for use together. Among the most successful areas along those lines is the strategy of mixing multiple channels of 1553, ARINC-429, Serial I/O and other interfaces on one card. Other functions such Serial FPDP and Ethernet are also moving onto multifunction solutions.
The need to support legacy MIL-STD-1553 bus networks plays big in the multifunction board space. Though many decades old now, 1553 is used in a wide variety of systems such as tanks, ships, missiles and satellites. For example, the workhorse military transport C-130J Hercules (Figure 1) has a 1553 data bus linking its mission computers and back-up bus interface units. The aircraft’s network monitors and records the status of the aircraft’s structure and systems. Several vendors continue to support 1553 with board-level solutions that provide 1553, often included with other functions. Among those vendors are ACCES I/O Products, AIM-USA, Ballard Technology, Critical I/O, Curtiss-Wright, Data Device Corp., Excalibur Systems, GE Fanuc and Kontron America.
Figure 1
The C-130J Hercules, a workhorse transport aircraft for the military, has a 1553 data bus linking its mission computers and back-up bus interface units.
Ethernet and 1553
If there’s one interconnect that seems to have emerged as the great “glue” technology for the military, that’s Ethernet. The conflict between the needs of net-centric communication and the current situation where the vast majority of basic military equipment interconnects via MIL-STD-1553 can be easily resolved with the use of “Network Bridges” to these legacy data buses. Such a “Bridge” is now available from MBS Electronic Systems, which offers autonomous connectivity between MIL-STD-1553 and Full Duplex Gigabit Ethernet. This FPGA-based stand-alone module (Figure 2) is one of a family of Gigabit Ethernet interface modules, referred to as ÆSyBus modules, which provide a low latency connection to a range of military and aerospace data buses using UDP/IP protocol. The open source nature of this solution, combining Ethernet and UDP/IP protocol, allows these devices to be easily accessed by any networked computer and operating system without the need of any additional drivers or software infrastructure. Furthermore, these devices can be accessed simultaneously by up to 10 separate computers, which can individually log on to the module, configure and control its resources and automatically receive status and data messages, periodically or as needed.
Figure 2
This FPGA-based board is one of a family of Gigabit Ethernet interface modules, referred to as ÆSyBus modules, which provide a low latency connection to a range of military and aerospace data buses using UDP/IP protocol.
The MIL-STD-1553 ÆSyBus Module can be configured to operate as a bus controller, remote terminal or passive monitor. In all cases, terminal/bus status is collected with receive data for automatic transfer to the applications in accordance with the configured requirements of the user. A configurable hardware scheduler is also provided for accurate scheduling commands when operating as a bus controller. The modules are available in a robust conduction-cooled enclosure, with build options to meet various environmental conditions, or as interface cards that slot into a VME I/O-type enclosure.
Sensors Data Via Ethernet and FPDP
The military has warmed completely to the idea of using Ethernet as a high-performance interconnect technology. Its ubiquity and longevity make it hard to resist. Applying Ethernet to wide-band sensor I/O, Critical I/O offers SensorLink (Figure 3), a board-level solution that allows wideband sensors to be easily connected to, and managed over, 1 Gbit and 10 Gbit Ethernet networks. SensorLink enables system designers to implement an Ethernet “Sensor Fabric” for high-performance systems. The FPGA-based board is a fully self-contained sensor-to-10 Gbit Ethernet bridge. It bridges multiple parallel sensor data ports that can be configured as industry-standard parallel FPDP and FPDP II, high-speed parallel LVDS, or PCIe-to standard 1 Gbit or 10 Gbit Ethernet, without the need for any host processor at the sensor.
Figure 3
SensorLink provides a fully self-contained sensor-to-10 Gbit Ethernet bridge. It bridges multiple parallel sensor data ports that can be configured as industry-standard parallel FPDP and FPDP II, high-speed parallel LVDS, or PCIe-to standard 1 Gbit or 10 Gbit Ethernet, without the need for any host processor at the sensor.
With SensorLink, Ethernet data networks can be applied to even the most demanding real-time applications such as radar, data acquisition, sonar, FLIR, SIGINT, video distribution and signal processing. Completely self-contained and requiring no host processor, SensorLink allows sensor data to be streamed at wire speed with very low latency to other devices connected to the Ethernet network such as signal processors, workstations, storage devices or other SensorLink devices. SensorLink also greatly simplifies the management of sensors by allowing remote processors to configure, control and monitor them through the same Ethernet connection without interrupting the sensor’s real-time data flow. SensorLink allows system developers to directly leverage standard Ethernet networks without investing many man-years in software and compatibility testing.
Multifunction I/O on the Desktop
Multifunction I/O solutions are also moving onto the desktop for military system developers to do their development and test work. An example is Ballard Technology’s LP429-5 (PCI) and LE429-5 (PCIe) PC expansion cards for communicating with ARINC 429 and ARINC 717 systems. These feature-rich interfaces provide programmable dual redundant data buffers and deep built-in memory. Models offer 4 to 32 ARINC 429 channels, and up to 4 ARINC 717 channels, 16 input/output avionics level discretes, and IRIG time synchronization/generation. Avionics discretes can be used as general purpose I/O or linked in hardware to databus activity as triggers or syncs.
The Lx429-5 products support maximum data throughput on all avionics interfaces. Each channel is independently configurable for high or low speed operation. Messages can be captured by a sequential monitor for all channels, or via individual message monitoring. Notification of databus activity is handled through the onboard Event Log, which can be processed by polling or via an interrupt. To dramatically reduce the host CPU processing, the sequential monitor has a DMA mode that automatically moves records to host memory through PCI/PCIe bus mastering.
A Variety of Military I/O
Another important trend affecting military I/O is the emergence of multifunction board products. Semiconductor integration has enabled board-level products to cram multiple functions on a single card. Along just such lines, North Atlantic Industries (NAI) has made available ARINC 429/575 support for its wide range of VPX, VME, cPCI and PCI Multifunction boards. Known as the A4, it joins an extensive list of functions that are currently available from NAI. The ARINC 429/575 A4 provides up to six programmable ARINC-429/575 channels. Each channel is software selectable for transmit and/or receive, high or low speed, and odd or no parity, supporting multiple ARINC 429 and 575 channels simultaneously.
One major advantage of this multifunction approach is higher functional density, which reduces overall board count, thereby saving space and cost, reducing heat dissipation and increasing overall system reliability. Other available functions include A/D, D/A, Synchro/Resolver/ LVDT/RVDT Simulation and Measurement, CANBus, MIL-STD-1553, Synch/Asynch RS232/422/485, Discrete, TTL/CMOS, Reference Generator, Differential Transceiver and Resistance Temperature Detectors (RTD). The ARINC 429/575 function is supported on VPX, VME, cPCI and PCI Multifunction Boards with operating temperature ranges of -40° to +85°C and 0° to +70°C.
Small Form Factor Solutions
The era of the multifunction board has encroached on the PC/104 space too. Serving those needs, Data Device Corp. has teamed with Advanced Digital Logic (ADL) to supply PC/104-Plus and PCI-104 cards for use in applications that require MIL-STD-1553 or ARINC 429 interfaces. DDC and ADL have proven interoperability of DDC’s BU-65578C MIL-STD-1553 card and BU-65590C Multi I/O (1553 and 429) card with the ADL systems.
DDC’s cards (Figure 4) provide a mix of MIL-STD-1553 and ARINC 429 receive/transmit channels along with user-programmable digital discrete or avionics discrete I/O, selectable external or internal time-tag clock, and an IRIG-B time synchronization input and output. The cards have an intelligent hardware offload engine that dramatically reduces PCI bus and host CPU utilization, while storing 1553 monitor data in a convenient and portable IRIG-106 Chapter 10 file format.
Figure 4
The BU-65590C Multi I/O (1553 and 429) cards provide a mix of MIL-STD-1553 and ARINC 429 Receive/Transmit Channels along with user-programmable digital discrete or avionics discrete I/O, selectable external or internal time-tag clock, and an IRIG-B time synchronization input and output.
Another small form factor I/O approach is the Pico-I/O small form factor line of products from ACCES I/O Products. Its new model PICO-II8IDO4A is designed for expansion on Pico-ITXe single board computers. This dense, multifunction product features eight individually optically isolated inputs, four fully protected solid-state FET outputs capable of switching up to 3A each, and two 16-bit analog inputs. The circuit isolation makes the module ideal for use in control and instrumentation applications where high-voltage protection is required. Individual channel-to-channel isolation allows every channel to be physically and electrically separated from the others. In addition, the two 16-bit analog inputs provided by the PICO-II8IDO4A allow for the monitoring and control of a variety of system parameters such as temperature, voltage, humidity and more.
The tiny module occupies just half the area of a PC/104 board yet approaches the capability commonly found on the larger board standard. The PICO-II8IDO4A is especially useful in applications where high common-mode external voltages are present. Isolation is required to guard electronics from transient voltage spikes and offers greater common-mode noise rejection in electrically noisy surroundings containing industrial machinery and inductive loads. In addition to protecting industrial applications from accidental contact with high external voltages, the isolation provided eliminates troublesome ground loops. The PICO-II8IDO4A utilizes a high-speed custom function driver optimized for a maximum data throughput that is 50-100 times faster than the USB human interface device (HID) driver used by many competing products. This approach maximizes the full functionality of the hardware along with capitalizing on the advantage of high-speed USB 2.0.
Pushing the Boundaries
The trend toward greater levels of board-level integration isn’t slowing. One of the most comprehensive examples of a multifunction solution is Curtiss-Wright Controls Embedded Computing’s XMC-660. This multifunction mezzanine card combines wireless, GPS and cryptography to deliver portable, secure in-the-field wireless connectivity. The lightweight, small form factor XMC-660 is an ideal solution for quickly and easily adding high-performance trusted wireless communications to VME, VPX and CompactPCI embedded systems for applications including luggable computers, manpacks and secure laptop computers.
Designed for rugged environments, the XMC-660, based on the VITA 42 XMC standard, uniquely combines support for Wi-Fi 802.11 n/a/b/g communications, Zigbee 802.15 asset tracking, and GPS location services on a single plug-in mezzanine card, to deliver an ideal solution for systems integrators building embedded wireless networks. Power dissipation for the card is 7W (typical) / 8.4W (max). It requires only a 5V power supply from the basecard. All other necessary voltages are generated on board the XMC-660.
ACCES I/O Products
San Diego, CA.
(858) 550-9559.
[www.accesio.com].
Ballard Technology
Everett, WA.
(425) 339-0281.
[www.ballardtech.com].
Critical I/O
Irvine, CA.
(949) 553-2200.
[www.criticalio.com].
Curtiss-Wright Controls Embedded Computing
Leesburg, VA.
(703) 779-7800.
[www.cwcembedded.com].
Data Device Corp.
Bohemia, NY.
(631) 567-5600.
[www.ddc-web.com].
MBS Electronic Systems
Starnberg, Germany.
+0049-8151 918047.
[www.mbs-electronics.com].
North Atlantic Industries
Bohemia, NY.
(631) 567-1100.
[www.naii.com].
