Radisys EMC-PS50

EMC - Embedded Modular Computer
EPC - Embedded Personal Computer (EPC-21/22/23/24/26/26A/27)
EXM - EXpansion Module

Notice: I have NO personal experience with any Radisys EXM related system or components. All these files were retrieved via Internet Archive and were re-named to a shorter format. To me, there can only be one period in a file name, or you may get odd problems with web pages...

Use of any of the files or information on this page is AT YOUR OWN RISK. If you want a guarantee on this stuff, seek out any repair / service company that supports EXM / EPC devices.

If you have any files or experience with these devices, please reach to Louis Ohland.


EMC-PS50 Power Supply (fits outside of EXM chassis 115/230v)
            EMC-PS50  Manuals  

EXM-PS50 Power Supply (fits INSIDE of EXM slot! -DC12, -DC24, -DC48)
            EXM-PS50  Manuals 


REMOTE - Female DB15 used to provide remote control of  power supply and to signal the CPU through the backplane.

POWER ON - PSU providing power to backplane.

OVERTEMP - lit > 80* C.  At 100* C, PSU shuts off.

5VDC OK - 5V output voltage > 4.6V.

Fuse - IEC Pub. 127/III, 1.0A 250V (AC model)

ON / STBY - Internal circuits are live even though  power switch is in STBY (standby) position.

INPUT - 18x3 AWG type SVT or SJT cable

What the heck is the model of the green receptacle?
EMC-PS50-AC EMC-PS50-DC12 EMC-PS50-DC24 EMC-PS50-DC48
Input voltage 85-264 VAC,
47-440 Hz
10-20 VDC 21-32 VDC 40-64 VDC
Max input current 1.0 A 9.0 A 6.0 A 3 A
Fuse type IEC Pub. 127/III, 1.0A 250V IEC Pub. 127/I, 10A 250V IEC Pub. 127/I, 6.3A 250V IEC Pub. 127/I, 3.15A 250V

EMC-PS50 INPUT Receptacle

Pluggable Terminal Block  5.08 mm, 3 Positions


If you got an EMC-PS50 without the mating plug, this is the part. Look for "Pluggable Terminal Block" with  5.08 mm pitch spacing and 3 Positions. Whatever manufacturer, it needs to be able to take a minimum 18 AWG conductor, 250v at 1A.


REMOTE Connector

Pin Signal Pin Signal Pin Signal
1 GND 6 IRQ+ 11 OT+
2 FLT- 7 RST+ 12 SD-
3 OT- 8 +5V EXT 13 IRQ-
4 (not used) 9 GND 14 RST-
5 SD+ 10 FLT+ 15 +5V EXT

+5V EXT Current limited +5V output with max of 1A.
GND    This is chassis/logic ground.

All of these signals occur as pairs (+ and -).  Output signals will provide an uncommitted optoisolator collector/emitter, rated at 50V max, 50mA max. The phototransistor conducts whenever the particular condition exists.  Therefore, applying 5V to the + signal and GND to - signal will provide a TTL level output.  Input signals require a 5V potential to be applied across the pair to signal the condition.

FLT     FAULT output when 5V output falls below 4.6V.

OT    OVERTEMP output when heatsink temperature exceeds 80* C.

SD    SHUTDOWN input remotely turns PSU on or off.  Active only when front-panel power switch is in ON/REMOTE position.  As long as a 5V potential exists across these two lines, the PSU will remain in standby mode and will not provide power to the backplane. When the potential no longer exists, the PSU will again power the backplane.

IRQ    INTERRUPT input signals IRQ15 on backplane. This is a buffered (inverted) input.  Since IRQs are positive edge-triggered (with pull-up resistors), to signal the interrupt, apply a voltage across these 2 lines for a minimum of 100 microseconds.  This sets IRQ15 low.  When the power is removed, the pull-up resistor returns the line to +5V causing a positive edge which triggers the interrupt.

RST  -  RESET input signal causes remote hardware reset of CPU on backplane.


Rear Connector 15-pin male T&B/Ansley 371-21530-305X (or equivalent).  The female connector is a T&B/Ansley 376-21530-095X (or equivalent).  The signals are:
Pin Signal Pin Signal
1 ACF- 2 ACF+
3 IRQ- 4 IRQ+
5 RST- 6 RST+
7 (not used) 8 -12V
9 +12V 10 GND
11 GND 12 GND
13 +5V 14 +5V
15 +5V

Rear connector signals IRQ and RST (+ & -) are provided to pass the front-panel remote connector signals through to the backplane. These signals are defined below under the remote connector section.  In addition, when using the EMC-PS50-AC power supply, ACF (AC Fail + & -) is provided to signal a processor when the AC input fails.  ACF is tied to -I/O Channel Check on the backplane.

Cooling Requirements The unit is convection cooled, so no forced air in or around the unit is required.  However, the system should be installed so that a minimum of 5" of air space is provided on each of the three exposed sides of the power supply unit.  The heatsink temperature must not exceed 80°C.

Content created and/or collected by:
Louis Ohland, Peter Wendt, William Walsh, David Beem, Tatsuo Sunagawa, Jim Shorney, Tim Clarke, Kevin Bowling, Tomáš Slavotínek, and many others.

Ardent Tool of Capitalism - MAD Edition! is maintained by Tomáš Slavotínek.
Last update: 19 Nov 2021 - Changes & Credits | Legal Info & Contact