No, the following state-of-the-art power supplies can be used:

For 3U cards:

- 12 V ±10% / 6.5 A (70 W) main supply

- 5 V ±10% / 1 A (4.5 W) standby supply

For 6U cards:

- 12 V / ±10% / 14 A (150 W) main supply

- 5 V ±10% / 4.5 A (20 W) standby supply

- Isolated 48 V ±10% / 3.5 A (150 W) aux.

The CompactPCI Serial connectors are completely compatible with the IEEE 1101 standard, which is also the mechanical basis of parallel CompactPCI. The connector has segments. This means that depending on the board's function, not all connector segments are assembled. Especially connectors P2, P3, P4 and P5 are specified for user-defined I/O on peripheral cards and offer a total of 360 pins, 120 pins of which are normally defined as GND. If a rear I/O board is connected at the rear of the backplane, and the I/O functions are customized, the pin-out must correspond 100% with the front board.
The layout of the boards and backplane summarizes P2 and P3 as well as P4 and P5 as one hole-pattern block. As long as the block is completely assembled, you can populate it with any desired AirMax connectors. There are AirMax connectors with 6, 8 and 10 rows. The connectors are mechanically coded. A plug connector with 8 rows, for instance, cannot be plugged into a receptacle with only 6 rows.
The standard prescribes that block P2-P3 may be populated by two 8-row connectors, but also with one 6- and one 10-row connector. This makes for three possible P2-P3 configurations: 6-10, 8-8, 10-6. Block P4-P5 can be populated by 8-6 or 6-8. This makes a total of six different connector arrangements for customized I/O boards. The corresponding backplane must be populated by the receptacles matching the I/O board but uses the standard layout.

The principle of redundancy is often used to build up safe systems and is used to detect errors. Besides safety, availability is also of special importance for applications in critical areas. Availability is also achieved through redundancy. The computers have to compare and align their results. To do this, they need an interface which on the one hand offers a high enough data transfer rate and on the other hand guarantees absence of feedback. Ethernet, especially the electrically isolated communication standards (10/100/1000/10GBase-T) are particularly well-suited. To support the configuration of safe systems, additional features such as hot swapping are included beside Ethernet as the communication interface. A board can be removed from the system without interrupting the function of the other computers. As the communication between the boards is based on Ethernet, which implicitly supports hot swapping already, not even a special hot swap controller is needed for this function.
A double 2-out-of-2 system might for example consist of three CompactPCI Serial subsystems. Each subsystem would have its own independent (standard) backplane with possibly independent PSUs. The connection of the subsystems can be done via Ethernet and rear I/O.
For wiring 2-out-of-3 systems, a full-mesh architecture is well suited. A standard backplane accommodates three identical CPU boards. Switches, which are also redundant, can also be realized as independent CompactPCI Serial components on standard backplanes. The wiring of the subsystems among each other is possible with rear I/O.

Yes, in a very easy way by making use of the 1/10 Gb/s Ethernet mesh feature of the standard and based on COTS components: Every sub cluster can consist of 9 CPU boards, with the main CPU connecting to 8 (identical) sub CPUs. With e.g. an Intel Core i7 this sums up to 36 kernels. The total cluster connects 8 sub clusters by Ethernet and controlled by a central NAS. This makes a total of 288 kernels (plus management units). The complete configuration would fit into a 19” system with 20U, needing 3500 Watts. This is 50% less power and less volume compared to 1U server platforms.

Yes – physical addressing is a necessity for modular computer periphery. The base specification defines one system slot and up to eight peripheral slots. The system slot is recognized by a special signal (SYSEN), not needing any additional address information. Even if the base standard does not explicitly describe this, you can of course expand the eight peripheral slots using suitable bridges. Since a 19-inch card cage accommodates a maximum of 21 slots, 4 lines are provided for the distinction between these slots. Depending on the backplane position, these lines will be either left open on the backplane, permanently connected to ground, or connected to ground with a 1 kOhm resistor. This results in 24 different combinations.

To assure the compatibility of different manufacturers, the CompactPCI Serial specification prescribes the order in which interfaces like SATA must be implemented on the system slot, if not all 8 interfaces can be supported. The physical addressing of CompactPCI Serial is simple and functional. It is compatible with standards such as SFF-8485 (specification for Serial GPIO (SGPIO) Bus) for hard drive RAIDs.

Yes, conductive cooling is included in the base specification, using a board to board pitch of 25.4 mm instead of 20.32 mm and requiring a special backplane. The advantage is that standard 3U cards for forced air cooling environments can also be used in conductive cooling chassis by means of a cassette.

CompactPCI Serial is based on the proven mechanics of CompactPCI and thus able to meet – as an example – even the harsh requirements in a train. The EN 50155 for the electronic equipment in a train aims at a functionality of 24 hours a day for 20 years, i.e. about 175,000 hours. This is achieved by defining requirements which have to be met in all imaginable environmental conditions, e.g.:

• Ambient temperature up to -40..+85 °C and thermal shock of 3°C/s as a requirement when passing through a tunnel. Because of the extreme temperatures, the thermal increase rates and the humidity, the components and the PCBs have to resist condensation which occurs if the temperature rises from values below zero degrees.
• Relative humidity of an average 75%, followed by 30 consecutive days with a humidity of an average 95%. This means that in most cases the electronic equipment requires waterproof housings or coated assemblies.
• Pollution, e.g. conductive dust, oil mist, spray salt and/or sulfur dioxide. Conformal coating and housings with IP protection class prevent the negative consequences.
• Forced air cooling should be avoided because it requires increased maintenance work. Pure convection cooling requires a suitable board and housing design.
• Moving trains are subjected to a multitude of electromagnetic disturbances. The transient burst resistance has to be proven according to EN 50121-3-2 and EN 61000-4-4. Resistance against radio disturbances has to conform to EN 50121-3-2 and electromagnetic radiation to EN 50121-3-2.
• Regarding shock and vibration the EN 50155 describes test methods and limit values which are defined in EN 61373.
• For the power supply in railway equipment additional requirements apply, such as fluctuation of the input voltage (66 to 154 VDC), ripple of the input voltage and input voltage surges. These power supplies are available as COTS products for CompactPCI and thus also for CompactPCI PlusIO and CompactPC Serial.

Yes – hot-plug is an integral part of the CompactPCI Serial specification. Reasonable applications reach from pluggable hard disks via RAID systems and PCI Express MiniCards up to complex clusters. Most technical issues are solved upfront because CompactPCI Serial is consequently based on serial interconnects. Ethernet, USB, PCI Express and SATA support hot-plug per se. A few inexpensive measures have been necessary to support this in a 19“-system according to IEC 1101:

• „Soft start“ of the power supply (state-of-the art with modern voltage regulators)
• Recognition of a removed board by physical adressing on the backplane
• Switch to start plug-off/in (as already integrated in the CompactPCI handle)
• Interface to the hot-plug controller via SGPIO or SFF-8485 (standard for RAID controllers)

Yes, two slots are connected to the system slot via PCI Express x8 interfaces that can be equipped with high-performance graphics cards. This works with standard backplanes without additional measures like switched fabrics, i.e. without additional costs and loss of performance. The remaining slots are connected via a PCI Express x4 interface, so that all graphics cards can also be plugged into every peripheral slot, with still sufficient performance for most applications. Modern graphics chips are able to control up to four high-resolution displays simultaneously via DisplayPort. A CompactPCI Serial system can accommodate up to eight graphics cards (without bridges), making it possible to control 32 displays with the corresponding software.

CompactPCI Serial permits the direct connection of Ethernet mezzanine cards to the backplane, thus extending a system to maximum 8 additional links for star, ring and mesh configurations.

CompactPCI Serial is mechanically based on IEC1101 which guarantees that mezzanine modules that have been designed for 3U and 6U boards – PMC, XMC and M-Modules – are also compatible with CompactPCI Serial. One PMC/XMC or two M-Modules fit on a 3U board, two PMC/XMC or three M-Modules fit on a 6U board. Electrically, the control of XMC modules is especially easy via PCI Express. Hot-plug support is possible, too. PMC modules are based on PCI and need a PCIe-to-PCI bridge – standard components are available on the market. M-Modules are based on an older “bus” wherefore a bridge would be typically realized in an FPGA.

Symmetrical multiprocessing is one technique to build redundant, safety-critical systems. For this the (Ethernet) pin assignment of the system and the peripheral slot must be congruent. A pin informs the plugged board whether it is located in a system or peripheral slot. This way, it is possible to plug a system slot board into each peripheral slot – no additional switches are needed.

Classic computers such as PCs have a hierarchical structure. At its "center" there is the computer that is surrounded by peripherals like the points of a star. This is independent of how the peripherals are controlled: via PCI Express, USB or SATA. In modular systems the system slot must now provide a large number of connections because of the star topology. The backplane must spread all of these connections to the peripheral slots without needing too many layers. The system slot is the center of the star. Each peripheral board is a symmetrical point. This is inexpensive and simple but assumes suitable connectors.

CompactPCI Serial offers the option of using up to 96 pin pairs or 192 single pins even for 3U boards. These pins are all embedded into ground pins and are therefore shielded. For 6U boards more than 300 pin pairs or more than 600 single connections are available. Apart from the higher pin density these connectors also come with a better transmission behaviour with high frequencies. This allows to achieve data rates of 10 Gb/s and more for differential signals. On 3U boards only the upper (Ethernet) and the lower (SATA, USB, PCI Express) connector are defined. Another 4 connectors are completely free for user defined I/O.

CompactPCI Serial completely does without a definition of the rear I/O connector and even leaves out the backplane in this area. The individual connector of the front board directly meets the corresponding connector of the rear I/O board. This approach helps to support the high bandwidths of digital communication or to handle highly sensitive signals in the field of measurement engineering. E.g. special connectors with a high signal-to-noise ratio of the front board can directly contact the rear I/O board or the front board can directly meet any desired optical connector of the rear I/O card.

The use of switches and bridges causes higher costs for the infrastructure, requires special software for the configuration and does not prevent that customer-specific backplanes are needed. CompactPCI Serial can do without because the pin-out for the serial point-to-point connections is fixed and identical for each (peripheral) card.

To keep things most simple for the users, they should be able to put any board into any slot. This requires that every slot defines identical interfaces. Every slot supports USB and PCI Express as well as Ethernet and SATA. The CPU centrally controls all interfaces, and distributes the signals to each of the eight peripheral slots via the backplane. This architecture is called a star topology and in the case of CompactPCI Serial does not need any further hardware like switches, bridges or fabrics, making it simple and inexpensive. This is also important for standards like Mini PCI Express cards for example, which expect USB as well as PCI Express support.

A full Ethernet mesh is a connection using a backplane wiring pattern where each slot has a dedicated connection to all other slots. CompactPCI Serial supports a system slot and 8 peripheral slots. Each of these 9 slots is connected with each of the other 8 slots via the backplane.

CompactPCI Serial permits to lead eight Ethernet interfaces to the backplane that are based on IEEE802 Base-T standards for copper cables. Base-T is low-priced, robust, flexible and future-safe, giving more than one advantage over 1000Base-BX (1 Gb/s) or 10GBase-BX4 (10 Gb/s), which need special PHYs (even redundant for safety):

• Base-T standards are the most future-safe Ethernet standards. Millions of nodes installed worldwide are based on them.
• Research has already begun on an extension to 100GBase-T – still compatible to existing installations with lower data rates even down to 10Base-T.
• The PHYs are often already integrated in the Ethernet controller itself.
• The Base-T standards are interoperable without additional software overhead (auto negotiation).
• As a rule, from 1000Base-T on, there is a fault tolerance within the connection. Modern 1000Base-T PHYs for example build up at least one 100Base-T connection if a wire pair is disturbed.
• The diagnosis capability of Base-T PHYs leaves almost nothing to wish for.
• Electrical isolation is possible at least optionally, which ensures the absence of feedback from the boards. This is important for redundant, safety-critical systems.
• Line lengths of up to 100 meters allow interconnection of loosely coupled computers. Using low-priced standard Ethernet switches complex networks can also be realized.

CompactPCI Serial permits to lead a total of eight PCI Express interfaces to the backplane. These links can be used to control eight PCI Express-based peripheral boards. Six of these interfaces are equipped with four lanes and reach data rates of 1000 MB/s with PCI Express Gen1 or 2000 MB/s with PCI Express Gen2 per direction. For applications that need higher data rates (like image processing) the remaining two PCI Express links support eight lanes each.

USB is a widely used standard for the connection of peripheral devices like keyboard and mouse, USB Flash drives and external hard disks especially to mobile computers. Nearly all modern laptops also provide Express card slots and support USB internally for the connection of PCI Express MiniCards. USB brings inexpensive technology also into modern, modular, industrial computers.

With SATA on the backplane each of the 8 peripheral slots can be used as a hard disk slot that is directly controlled by the system slot. The mechanics offers all characteristics which are required for a RAID shuttle:

• Robust plug-in mechanics
• Switch in the handle to signal removal of the hard drive
• (Blue) LED to signal that the board may be removed

CompactPCI Serial includes more mechanisms which are required for a RAID system. For example it is possible to determine the disk to be changed via the physical addressing. A management bus which is compliant to the SFF 8485 specification provides the necessary communication between the RAID controller and the shuttle. It defines a serial GPIO bus (SGPIO) especially in connection with Serial Attached SCSI (SAS) and Serial ATA (SATA). It serves for exchanging data between the RAID controller and the hard disk shuttle. It can transmit simple status information (e.g. "switch closed", "hard-drive powered") and control LEDs or monitor the power supply of the hard drive. Using SATA Port Multipliers, even more than eight drives can be controlled in a CompactPCI Serial system.

• SATA or SAS is the interface for mass storage devices like hard drives
• USB is established for WiFi components and loosely coupled peripheral devices like keyboards, touches, external hard drives etc.
• Ethernet is used as interface for multiprocessing and as field bus for controlling local I/O
• PCI Express is used for closely coupled peripherals