6U - FAC - Flowthrough Air Cooled

Rugged OPEN COTS ATR - In 5, 7 & 12 slot versions. Certified per MIL-461E & MIL-810F for immediate deployment. Applications up to 700 watts. Configure Now

6U - FAC - Flowthrough Air Cooled

Custom COTS - Customer configurable & loaded with options: Extended bottom & top covers, front panel connectors, logos & silk screening, etc. Configure Now

6U FAC Description

Non-sealed, 0.8" pitch, high performance 6U chassis where external air is directly forced over electronic payload modules using rear exhaust fans. This highly efficient thermal management technique is suitable for full PSU wattage applications.


Heat generated within the enclosure is dissipated via forced air convection. An exhaust fan (or air plenum) draws ambient air through the chassis carrying unwanted heat from payload modules. Heat is also conducted through the chassis metalwork to the environment.


The 6U FAC chassis is available in 5, 7, & 12 slot versions ( ½ ATR, ¾ ATR, 1 ATR), supporting VME, cPCI, VPX, VPX-VME & cPCI-VME hybrid backplanes. A total PSU power of up to 1050 watts may be installed. Custom modifications can be designed upon request.

CM-ATR-45/FAC Layout

Internal layout is divided into 3 independent metallic partitions. I/O section at the front, card-cage in the middle & PSU section at the rear. This improves EMI/EMC performance & reduces PSU noise on system electronics.

Attention to I/O flexibility and easy board integration; allowing the intermixing of wedgelock IEEE P1101.2 conduction cooled boards, IEC-297 air cooled modules, Compact PCI 1101.1/IEC/118/ CD and VPX VITA 46.0/.1/.10/.3/.4/.7 air cooled boards.

6U FAC Performance



Slots:5 | 7 | 12   0.8"

Open (Ambient Air):

≤ 700W

The 6U FAC chassis is suitable for high wattage applications that demand superior cooling capability.

FAC - Chassis Global Thermal Resistance (CGTR) coefficient:
ΔT/W = 0.057°C (½ ATR) | 0.052°C (¾ ATR) | 0.041°C (1 ATR) .

FAC - Chassis Payload Thermal Resistance (CPTR) coefficient:
ΔT/W = 0.075°C (½ ATR) | 0.066°C (¾ ATR) | 0.046°C (1 ATR).
For reliable operation it is recommended the maximum Payload Power not be exceeded. Subject to operating conditions.

All CM 6U ATR chassis are delivered tested, qualified and certified per Military Standards MIL-STD-461E & MIL-STD-810F.

6U FAC Backplanes

CM 6U FAC military backplanes are available in VPX, VMEbus, cPCI, or combinations of VPX-VME64 or cPCI-VME64 hybrids, providing standard bus slot and signal daisy-chain functionalities. Designed to improve card-cage mechanical performance with 0.8 inch pitch slots & implement many features.

CM ATR FAC - 6U VME | cPCI Backpanes

All 6U backplanes install specific TTL logic circuitry for driving up to 8 front panel user LED indicators. Units fitted with a Temperature Supervisory Unit will also drive an additional panel LED TEMP (over/under temperature indicator).

  • VME64x backplanes conduction-cooled IEEE-1101.2 & air-cooled IEC-297/IEEE.1101.1 modules.
  • Compact PCI backplanes according to IEC 1076 / PCI 1101.10/IEC 48D/118/CD standards.
  • VPX backplanes conform to VITA 46.0/.1/.10/.3/.4/.7.
  • VPX-VME64x Hybrid feature mesh-fabric slots that support both VITA46 (VPX) & legacy VME64x slots.

All FAC backplanes integrate a Temperature Supervisory Unit (TSU) with panel LED (over/under temperature) that controls Power Supply & Fan operation. Remote optoisolated control switches for ‘Battle-short’ & chassis PSU ‘on/standby’ are fitted as standard but not activated by default.

CM ATR FAC - 6U VPX | VPX-VME Backpanes

CM 6U military backplanes allow unlimited pin I/O wiring capability. Flexible top & bottom wiring integration is facilitated by a standard 25mm bottom cavity clearance to avoid requiring a custom backplane.

Final slots in 12 & 7 slot chassis allow for bus functionality & contain power/control provisions to accept a eurocard-size metallically caged Redundant PSU. A single slot RPSU up to 575W operates in parallel with main PSU on a load-sharing basis to minimize component stress.

Custom backplanes maybe designed upon customer request.

CM backplanes support one or two 100W power sockets for optional micro-size DC/DC military converters with user defined output voltage. The converters are useful for increasing the +5VDC or +3.3VDC power lines or for generating isolated positive, negative or bipolar auxiliary DC voltages.

CM ATR FAC - 6U cPCI-VME backplanes

Class 1 military power input connectors offer reliable shock & vibration interconnectivity between chassis internal modules and allows high DC current rates with low voltage drops & minimum contact heating.

6U backplanes are supplied with military conformal coating. Printed circuits boards are partially coated per MIL-I-4658C in areas in which do no affect VPX, VME, cPCI, or I/O connectors.

All 6U models integrate similar backplane electronics for easy switch-overs, retrofits or replacement parts.
Read More

6U FAC Power Supplies

6U FAC chassis PSUs support a wide variety of AC/DC input voltages (MIL-STD-704 & MIL-STD-1275) and customer defined DC power output combinations up to 1050 Watts. Available in different versions to suit input voltage requirments.


All PSU models are fitted with Power Fail Monitor, remote voltage sensing, output voltage trim-up, time-delayed protection fuses, rear fan fuse and DC/DC converter remote shutdown.

To comply with MIL-STD-461E, a high capacity integrated EMI/EMC input voltage filter is fitted as standard on all 6U models. PSUs are custom made to match the enclosure mechanics.

200VAC 3-Phase PSU versions incorporate AC/DC rectifier stage prior to the VICOR FIAM front-end modules.

DC PSUs are equipped with a VICOR military Filter and Attenuator Module (FIAM). This front-end device is fitted prior to the DC/DC converters to provide EMI filtering, inrush current limiting and transient protection.


Front-end FIAM modules are protected against DC reverse polarity. An optional reverse polarity diode may be fitted in series with power connector input pin IN (+).

Single-phase AC PSUs are fitted with a VICOR military Filter and Autoranging Rectifier Module (FARM) to provided EMI filtering, autoranging line rectification and inrush current limiting to meet MIL-STD-461E category A1b specifications for Electromagnetic Compatibility.

6U FAC PSUs incorporate isolated DC/DC converters & oversized hold-up capacitors to ensure proper operation during short power line failures. Outputs are protected against short-circuit, thermal-shutdown etc.


The PSU in FAC models is attached to the chassis rear panel to provide both conduction & convection cooling.

Forced air drawn through the chassis is exhausted, dissipating the majority of heat generated.

6U ATR FAC Features

6U FAC Rear Fan Assembly
Rear Fan Options
6U FAC chassis are equipt with either single or twin Rugged (-10°C to +70°C) exhaust fans or Military PX2 fans (-54°C to +125°C).
6U FAC LED Indicators
LED Front Panel Indicators
Up to 8 front panel LED indicators for chassis monitoring; power on/off status, system board failure, input voltage, temp., etc.
6U FAC Front Panel
Front Panel
Custom layout with client logo, connectors & silk-screening or a general purpose panel with MIL-C-38999 connectors is supplied.
6U FAC Panel Covers
Top/Bottom Covers
Optional High Profile, Heat Exchanger or High profile Heat Exchanger covers can be selected for additional wiring clearance & are removable.
6U FAC Chassis Metalwork
Chassis Metalwork
Precision machined aeronautical aluminum with MIL-DTL-5541F chromate coating. All panels & joints incorporate EMI gaskets.
6U FAC Mounting Tray
Mounting Tray
Low profile with quick release system offers easy insertion/removal capability, weight optimized with minimized dimensions.
EMI/EMC Filter
High capacity integrated EMI/EMC input voltage filter is fitted as standard on all 6U models to comply with MIL-STD-461E.
6U FAC Internal Air Recirculation
Air Recirculation
All 6U chassis incorporate a low profile internal fan pack to recirculate air, improving card-cage, PSU & module heat dissipation.
6U FAC Weight Optimized ATR
Weight Optimized
Enclosure sidewalls & rear panel are externally finned to decrease weight by up to 50% without sacrificing mechanical performance.


  • VPX, VME64, cPCI & Hybrid ready (0.8" Pitch)
  • Accepts Conduction & Air-cooled 6U Modules
  • Flexible Top & Bottom I/O wiring
  • In-line EMI/EMC MIL-STD-461F Filter
  • Up to 700W* Total Payload Power (30ºC Delta-T)
  • Integrated Temperature Supervisory Unit (TSU)
  • Integrated Rear fan guards
  • Dramatically increases payload MTBF by 5x*
  • Maintenance free operation
  • Front panel user indicators
  • Stand alone low weight ATR
  • Internal card-cage airflow recirculation
  • Independent Fan & Power Supply input voltage
  • Military Operating Temperature (-40°C | +85°C)
  • Customizable to specific requirements
  • Low Profile Mounting Tray with quick release
  • Manufactured with US MIL components
* Subject to operating conditions

6U ATR FAC Specifications

WIDTH 130 mm 170 mm 271 mm
HEIGHT 236 mm 236 mm 236 mm
DEPTH 390 mm 390 mm 390 mm
WEIGHT 5.7 Kg 7.2 Kg 10.8 Kg
CGTR COEFF ΔT/W = 0.057°C ΔT/W = 0.052°C ΔT/W = 0.041°C
CPTR COEFF ΔT/W = 0.075°C ΔT/W = 0.066°C ΔT/W = 0.046°C
SLOTS 5 712
PSU MAX POWER 400 Watts (28 VDC 300 Watts) 500 Watts (28 VDC 400 Watts) 1050 Watts (28 VDC 950 Watts)
PSU V-INPUT 28 VDC ±30%, 48 VDC ±30%, 72 VDC ±30%, 270 VDC ±30%, Autorange 90-132 VAC RMS & 180-264 VAC RMS 47-880 Hz, 3-Phase 200 VAC ±30% 47-880 Hz
STD BACKPLANE 6U (0.8" Pitch), VME64X or cPCI or VPX or Hybrid VME64X/VPX or VME64X/cPCI
BOARD FORMAT CCS: Conduction-cooled slots only or MCS: Slot-by-slot user configured card-cage allows intermixing conduction-cooled ANSI-VITA 48.2 & air-cooled ANSI-VITA 48.1 boards
EXT. REAR FAN 1 x Rotron PX2 1 x Rotron PX2 2 x Rotron PX3
F115-400 65 CFM 65 CFM 200 CFM
F200-400 120 CFM 120 CFM 280 CFM
F28 65 CFM 65 CFM 200 CFM
FRONT PANEL AREA 101 mm x 172.5 mm 141.5 mm x 172.5 mm 243 mm x 172.5 mm
I/O SUPPORTED 6 Power Pins (23 Amp) & 365 I/O Pins (5 Amp) 6 Power Pins (23 Amp) & 822 I/O Pins (5 Amp) 6 Power Pins (23 Amp) & 1057 I/O Pins (5 Amp)
OPERATING TEMP -40 °C to +85 °C Operating Temperature, -55 °C to 100 °C Storage Temperature
MTBF 25° GB 98,000 Hours, 65° AIC 32,000 Hours25° GB 86,000 Hours, 65° AIC 28,000 Hours25° GB 78,000 Hours, 65° AIC 24,000 Hours


These highly optimized 6U chassis incorporate all proprietary technologies, features and well established mechanical & electrical solutions developed during the past 27 years.

FAC:Flow-through airflow open enclosure.

S:Standard sealed contaminant-free enclosure.

SEF:Sealed with Extended Fins contaminant-free enclosure.

SEF-HP:Sealed with Extended Fins + 18/20 Heat Pipes contaminant-free enclosure.

HES:Sealed fitted with 4 integrated heat exchangers contaminant-free enclosure.

HES-1Sealed 1" pitch, fitted with 4 integrated heat exchangers contaminant-free enclosure.

SIXHEX:Sealed fitted with 6 integrated heat exchangers contaminant-free enclosure.

SIXHEX-1:Sealed 1" pitch, fitted with 6 integrated heat exchangers contaminant-free enclosure .

SIXHEX-16HP:Sealed fitted with 6 integrated heat exchangers & 16 heat pipes contaminant-free enclosure.

SIXHEX-20HP-1:Sealed 1" pitch, fitted with 6 integrated heat exchangers & 20 heat-pipes contaminant-free enclosure.

SEVENHEX-CHP-1:Sealed 1" pitch, fitted with 7 integrated heat exchangers & 32, 36 or 46 heat-pipes contaminant-free enclosure.

6U ATR MIL Certificates

6U ATR FAC Ordering Information

Generic Part Number:
CM-ATR-S5 /CT /B /I /W /3.3 /D1 /D2 /R /S /FP /TC /BC /CS /F /G /C
/S5 Enclosure Size
  • CM-ATR-25: ½ ATR - 5 Slots (0.8" Pitch).
  • CM-ATR-35: ¾ ATR - 7 Slots (0.8" Pitch).
  • CM-ATR-45: 1 ATR - 12 Slots (0.8" Pitch).
/CT Enclosure Cooling Technique
  • FAC: Flowthrough (0.8" Pitch) Air Cooled enclosure (open).
/B Backplane Type
  • VME64x: Military VME64x Backplane with 5 row 160 pin J1/J2 and 95 pin J0 connectors.
  • VME64xK: Military VME64x Backplane with 5 row 160 pin J1/J2 & 75 pin key-slot J0 connectors.
  • cPCI: Military Compact PCI Backplane.
  • VPX: Military VITA 46 VPX Backplane.
  • VPX/VME64x: Hybrid VPX mixed with VME64x Military Backplane.
  • cPCI/VME64x: Hybrid cPCI mixed with VME64x Military Backplane.
/I PSU Input Power Voltage
  • 28VDC: 28 VDC Input.
  • 48VDC: 48 VDC Input.
  • 72VDC: 72 VDC Input.
  • 270VDC: 270 VDC Input.
  • 90-264VAC: Autorange 90-264 VAC @ 47-880Hz Input.
  • 200VAC-3Ph: 200 VAC 3 Phase @ 47-880Hz Input.
/W Power Supply Unit
CM-ATR-25 - 5 Slot
  • 300W: 28 VDC (+5 VDC @20A, +3.3 VDC @5A, ±12 VDC @8A).
  • 400W: All PSUs (+5 VDC @20A, +3.3 VDC @5A, ±12 VDC @12A).
CM-ATR-35 - 7 Slot
  • 400W: 28 VDC (+5 VDC @40A, +3.3 VDC @5A, ±12 VDC @8A).
  • 500W: All PSUs (+5 VDC @40A, +3.3 VDC @5A, ±12 VDC @12A).
CM-ATR-45 - 12 Slot
  • 950W: 28 VDC (+5 VDC @80A, +3.3 VDC @45A, ±12 VDC @16A).
  • 1050W: All PSUs (+5 VDC @80A, +3.3 VDC @45A, ±12 VDC @21A).
All PSUs = All PSUs except 28 VDC input
28 VDC = 28 VDC input only

/3.3 3.3VDC (CM-ATR-25 & CM-ATR-35 only)
  • 3.3-75W*: 3.3VDC @ 22A (in Lieu of 3.3 VDC @ 5A), Optional DC/DC AUX0 converter on Backplane fitted for 3.3VDC
  • NOTE: Option suited for 1st generation PSU models 300W/400W/500W. Note: If /3.3-75W is not selected, DC/DC power socket AUX0 remains free to the user
/D1 DC/DC AUX1 (CM-ATR-35 & CM-ATR-45 only)
  • D1: 100W Optional DC/DC Converter on Backplane. User defined output. Auxiliary DC/DC output options: +2VDC 50W, -2VDC 50W, +3.3VDC 75W, -3.3VDC 75W, +5VDC 100W, -5VDC 100W, +12VDC 100W, -12VDC 100W, +15VDC 100W, -15VDC 100W, +28VDC 100W, -28VDC 100W, +48VDC 100W, -48VDC 100W.
  • Ordering Examples: 48-100W » 48VDC @ 2A | -5-100W » -5VDC @ 20A | 2-50W » 2VDC @ 25A.
/D2 DC/DC AUX2 (CM-ATR-45 only)
  • D2: Optional user defined output DC/DC converter on backplane.
/R Redundant Plug-in PSU
CM-ATR- 35 & CM-ATR-45 only
  • RA-475W: 28 VDC (+5 VDC @40A, +3.3 VDC @22A, ±12 VDC @8A).
  • RA-575W: All PSUs (+5 VDC @40A, +3.3 VDC @22A, ±12 VDC @12A).
/S Temperature Supervisory Unit
  • TSU: Temperature Supervisory Unit.
/FP Front Panel Layout
  • CMP: Standard CM front panel fitted with MIL-C-38999 connectors.
  • UDP: User defined front panel layout (requires customer drawing).
/TC Chassis Top Cover
  • STC: Standard Top Cover. ‡ 20mm.
  • HTC: High-profile Top Cover. ‡ 35mm.
  • HETC: Heat Exchanger Top Cover. ‡ 20mm.
  • FTC: Low Profile Top Cover with cooling fins. ‡ 20mm.
/BC Chassis Bottom Cover
  • SBC: Standard Bottom Cover. ‡ below backplane 25mm.
  • HBC: High-profile Bottom Cover. ‡ below backplane 50mm.
/CS Chassis Card-Cage Slot
  • MCS: Mixed Card-cage Slots (conduction-cooled & air-cooled boards).
  • CCS: Conducton-cooled Card-cage slots (conduction-cooled boards only).
/F Rear-mounted Fan Assembly
Fans available for CM-ATR-45
  • F115-400: 2x Rotron PX3 Military fan fitted for 115VAC @ 400Hz (100CFM each).
  • F200-400: 2x Rotron PX3 Military fan fitted for 200VAC @ 400Hz 3-Phase (140CFM each).
  • F28: 2x Rotron PX3 Military fan fitted for 28VDC (100CFM each).
Fans available for CM-ATR-35 & CM-ATR-25
  • F115-400: 1x Rotron PX2 Military fan fitted for 115VAC @ 400Hz (65CFM).
  • F200-400: 1x Rotron PX2 Military fan fitted for 200VAC @ 400Hz 3-Phase (120CFM).
  • F28: 1x Rotron PX2 Military fan fitted for 28VDC (65CFM).
Vehicle air-plenum assembly
  • VAP: Vehicle Air-Plenum according to customer specifications (external forced air source).
/G Fan Finger Guards
  • STDG: Standard Rotron PX2/PX3 finger guards.
  • EMIG: Optional EMI shielding finger guards with honeycomb filter.
  • ANF: Optional finger guards with low acoustic noise filter (-6dB).

/C Chassis Color
  • B: Black, G: Navy Grey, E: Army Dark Earth, W: White, R: Red, PT: Platinum, YW: Yellow, GN: Green, BLU: Dark Blue, CR: Chromate MIL-C-5541 or O: Other (user defined).
Part Number Example:
  • 1 ATR, 12 slot, 6U VMEbus Avionics Enclosure.
  • Flow-through Air Cooled Enclosure.
  • Extended 12 slot VME64x Backplane for 6U boards fitted with 5 row 160 pin VME64x J0/J1/J2 connectors.
  • 28VDC input Power Supply Unit with 950W (+5VDC @80A, +3.3VDC @45A, ±12VDC @16A).
  • (+) 24VDC @ 4A DC/DC AUX1 user output on Backplane.
  • (+) 48VDC @ 2A DC/DC AUX2 user output on Backplane.
  • Standard CM Computer Front Panel.
  • Standard low profile top cover.
  • Extended high profile hat bottom cover.
  • Universal, mixed card-cage slots.
  • 2x Rotron PX3 military fan fitted for 28VDC installed at the rear (200CFM total).
  • Standard Rotron finger guards.
  • Enclosure black color.