Vector Series 2370: Horizontal 6U Card Packaging with Hot-Swap Filtered Cooling

Packaging 6U electronics in a short rackmount enclosure creates a mechanical problem that is not solved by card height alone.
The enclosure must provide enough space for the front cards, rear I/O, backplane, power conversion, airflow, service access, and rack integration while maintaining a controlled and repeatable system architecture.

The Vector Series 2370 addresses this problem with a horizontal card chassis designed around 6U Eurocard packaging. It supports a 6U × 160 mm front card cage, a 6U × 80 mm rear cage for rear transition modules, standard 19-inch rack installation, and a filtered hot-swap cooling assembly. The result is a compact packaging platform for VME, VME64x, CompactPCI, and VPX systems where rear I/O and serviceability are part of the system design rather than afterthoughts.

A horizontal approach to 6U packaging

Most rackmount card systems place circuit cards vertically, with the card edges parallel to the rack height. Series 2370 instead installs the cards horizontally. This changes the way the enclosure uses its available volume.

The front cage accommodates 6U × 160 mm cards. A second cage behind the backplane accommodates 6U × 80 mm rear transition modules, or RTMs. The arrangement allows the front card and its associated rear I/O module to occupy corresponding positions through the backplane.

That separation is important in systems where front-accessible processing, acquisition, control, or communications cards must connect to rear-panel I/O. It avoids routing every external interface to the front panel and provides a structured way to separate user connections from service and board access.

The horizontal layout also makes it possible to package 6U systems in chassis heights from 2U through 5U:

2U: 3.47 inches, or 88.14 mm
3U: 5.22 inches, or 132.59 mm
4U: 6.97 inches, or 177 mm
5U: 8.72 inches, or 221.49 mm

The chassis width is 19 inches, compatible with rack mounting under EIA-310-D. The specified depth is 11.65 inches, or 296 mm, excluding the rack handles.

Backplane compatibility and mechanical standards

Series 2370 accepts 6U-high VME, VME64x, CompactPCI, or VPX backplanes. The chassis is identified as compliant with the mechanical practices of:

IEEE 1101.1
IEEE 1101.10
IEEE 1101.11

These standards establish the mechanical framework for Eurocard-based plug-in systems, including board dimensions, subrack interfaces, front-panel features, electromagnetic compatibility provisions, and rear plug-in units.

IEEE 1101.11 is particularly relevant to the rear cage because it addresses rear plug-in units commonly used as RTMs. The 6U × 80 mm rear cage provides the mechanical space associated with this rear-transition architecture.

Mechanical compatibility does not, by itself, define the electrical implementation. A VME64x, CompactPCI, or VPX system still requires the correct backplane connector arrangement, routing, power distribution, signal mapping, and slot configuration for the selected bus architecture. For VPX systems, for example, the backplane and module interface must follow the applicable VITA specifications in addition to the common mechanical envelope.

Vector maintains separate backplane offerings for VME, VME64x, CompactPCI, and OpenVPX applications. The backplanes product area provides the appropriate starting point for matching a Series 2370 mechanical configuration to a bus-specific interconnect design.

Cooling architecture: left intake and right exhaust

The Series 2370 airflow path is defined by a left-side air intake and right-side exhaust. This establishes a predictable cross-flow through the chassis and gives system integrators a clear basis for rack-level airflow planning.

The intake includes a hot-swap fan tray with an air filter. The fan tray is located on the left side only. From an engineering perspective, this arrangement combines three functions:

It establishes the direction of cooling air through the enclosure.
It filters incoming air before it reaches the card cage.
It permits fan-tray replacement without requiring a full chassis disassembly or a planned system shutdown.

The use of a filter introduces a maintenance requirement: filter loading must be considered during service planning because airflow resistance increases as contamination accumulates. A filtered intake is therefore most effective when the maintenance interval, environmental conditions, and replacement procedure are defined as part of the system configuration.

The hot-swap feature also requires a system-level assessment. Fan replacement without power removal can reduce service interruption, but the equipment must remain within its thermal operating limits during the exchange. The allowable service interval depends on the card power dissipation, airflow distribution, fan-tray design, and the thermal mass of the installed electronics. The chassis architecture supports the service strategy; the final thermal margin remains application-dependent.

Compactness versus cooling capacity

Reducing chassis height from a conventional 6U enclosure to a 2U, 3U, 4U, or 5U package can save rack space, but compactness reduces the available internal volume for air movement, cabling, power supplies, and service access.

Series 2370 addresses that tradeoff by using horizontal 6U card installation rather than attempting to fit vertically oriented 6U cards into a low-profile rack chassis. The design makes the card format and rack height independent variables: the cards remain 6U in electrical and mechanical architecture, while the enclosure height is selected according to the required system configuration.

This approach is useful when the system needs 6U backplane connectivity but does not require a full-height vertical-card chassis. It also places greater importance on:

Card-to-card airflow uniformity
Clearance around high-dissipation components
Backplane and cable obstruction
Fan-tray access
Filter service access
Power-supply heat dissipation
Rack inlet and outlet clearance

The specified environmental range is 0°C to 50°C operating and −40°C to 75°C non-operating. These values define the published temperature envelope for the chassis configuration; they do not replace a thermal analysis of the installed electronics. System designers should evaluate the worst-case card power, inlet temperature, filter condition, fan operating state, and rack airflow interaction.

Materials used in the assembly are specified to meet UL94V-0 flammability requirements. The chassis also identifies compliance considerations for UL, FCC, and CE marking, subject to the complete system configuration and applicable certification process.

Rear I/O and maintainability

Rear transition modules improve I/O organization, but they add depth and create another service interface. The Series 2370 provides a dedicated 6U × 80 mm rear cage for this purpose.

The engineering benefit is clear: I/O can be routed through rear connectors while the front card cage remains dedicated to board insertion, status access, and service. This can simplify rack wiring and reduce the need to disconnect front-panel cables when replacing a processing or interface card.

The tradeoff is that rear I/O becomes dependent on correct alignment between the front card, backplane, and RTM. The rear cage, backplane connectors, card guides, retention hardware, and cable exit paths must all be controlled during assembly. Connector engagement and extraction forces also need to be considered when the chassis is installed in a rack with limited rear access.

For production systems, this is where configuration control becomes important. A chassis should be documented not only by its enclosure model, but also by its backplane revision, card-slot population, RTM assignment, power configuration, fan-tray configuration, and monitoring provisions.

Power supply options and redundancy

Series 2370 supports plug-in power supplies in 3U or 6U × 8HP × 160 mm formats using PICMG 2.11 Revision 1.0 interfaces.

The chassis can be configured with one, two, or three plug-in power supply modules. Multiple modules can be used to increase total available power capacity or to implement N+1 redundancy for hot-swap applications.

These are different design objectives:

Capacity expansion uses multiple supplies to meet the system’s aggregate voltage and current requirements.
N+1 redundancy provides an additional supply beyond the number required for the load, allowing continued operation after the loss or removal of one module, subject to the supply architecture and load-sharing design.

Power selection should account for steady-state load, startup current, transient demand, derating, cooling requirements, and the voltage rails required by the selected backplane and cards. Redundancy does not eliminate the need to validate power distribution, fault behavior, connector ratings, and thermal performance.

Vector provides a dedicated plug-in power supply section for selecting compatible supply configurations.

Monitoring and custom configuration

The Series 2370 supports system-voltage monitoring locally through LEDs and remotely through RJ-45 or RS-485 interfaces. This allows the monitoring method to be selected according to the system’s maintenance and integration requirements.

Local LED indication is useful during installation, bench test, and rack service. Remote monitoring is more appropriate when the chassis is integrated into a larger platform where power status, alarms, or system health must be observed without direct access to the enclosure.

Available custom options include:

Custom backplane design
Alternate power supply configurations
Mechanical modifications
Local voltage monitoring
Remote monitoring through RJ-45 or RS-485

These options should be treated as controlled configuration elements. Changes to backplane routing, mechanical cutouts, power architecture, or monitoring interfaces can affect thermal behavior, electromagnetic compatibility, service procedures, and production test requirements.

System assembly and test readiness

The Series 2370 is specified as fully assembled, wired, and tested. For a complete system build, that distinction matters. The enclosure, backplane, power supplies, cooling assembly, monitoring hardware, card guides, rear cage, and wiring must operate as an integrated configuration.

A test-ready system reduces the risk of discovering mechanical interference, connector mismatch, inadequate cable routing, or power-distribution issues only after the equipment reaches system integration. It also supports traceability when the build is documented against a defined bill of materials, drawing set, backplane revision, and test record.

Vector’s broader chassis and system enclosure portfolio includes vertical-card, horizontal-card, and ruggedized packaging families. The Series 2370 occupies the horizontal 6U position for applications that require a compact rack height, rear I/O, standard bus backplane support, and serviceable filtered cooling.

The primary engineering principle is straightforward: compact packaging is effective only when cooling, rear I/O, power, and maintenance are designed as one system. Series 2370 provides the mechanical framework for that integration, while the installed card set, backplane design, power budget, airflow demand, and service requirements determine the final system performance.