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  Electrical Optical Passive Interface Test Equipment Enclosures Other

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  RS422 1 of 2 Select Chassis  
  Description 701395

The Technisys RS422 1 of 2 Select Chassis is a fully integrated device designed to allow 1 of 2 RS422 inputs to be selected by RS232 control or a local manual override. It is housed in a 1U rack mount enclosure and includes an auto-ranging power supply for use internationally.

I/O is through D15F connectors. A three position, locking toggle switch (SELECT) is located on the front panel to provide the ability to select either INPUT A or B for output. Front panel LEDs indicate which input has been selected. In this manual mode, the processor is by-passed and control is implemented directly from the front panel switch.

When the front panel SELECT switch is placed in REMOTE position, the appropriate LED illuminates and input selection is controlled by a command sequence from either of the two independent RS232 serial ports through DB25F connectors. There is an input buffer for each serial port so characters are continually received from either serial port or both.  Input counters and timers prevent problems from a jabbering serial port.

On power failure, the unit defaults to INPUT A through normally closed (NC) relays. These relays are held open during normal operation so that true RS422 receivers and drivers can be employed to receive and transmit active RS422 signals. When power is off or has failed, the relays return to their NC position and signals will pass through without being buffered.

  • Provides 1 of 2 input selection for RS422 signals
  • Two fully independent RS232 control ports
  • Channel Select indicators for each input channel.
  • Local manual override select switch
  • Failsafe throughput on power loss
  • Standard 1U rack mountable.
  • Powered from 120/240VAC auto-ranging, international power supply
Height:         1.69” (4.1 cm) (1U)
Width:          19.0” (48.3 cm)
Depth:          13.75” (34.9 cm) overall including front and rear panel hardware
Weight:        5.40 lbs. (2.45 kg approx.)

Electrical-power requirements
85-265VAC, 47-66 Hz, 15 Watts maximum
Power connector:           IEC-320 connector
Ground connection:        10-32 PEM nut near IEC connection

Signal I/O Connectors: 15 pin Receptacle D Sub-miniature connectors
RS232 Control Ports: 25 pin Receptacle D Sub-miniature connectors

Signal Throughput, Data Rates and I/O Hardware:
Signal rates: 10bps to 10Mbps at 1,000 feet using TIA/EIA RS422 compliant 120 Ohm termination and receiver.
Signal quality: BER of 1x10-12 at any rate
Propagation delay: 53 ns max.
Output skew: 1.0 ns max.
Differential signal (data port) connectors: DB15 F
Input amplitude (nominal): 5V p-p differential, +/- 200 mV sensitivity.
Absolute maximum: 25V differential, common mode or referenced to ground
The input for RS422 is properly terminated at 120 Ohms and cannot be altered without component replacement.

RS232 Serial Control Ports:
Baud:                                                    300 to 115.2 kbps per TIA/EIA RS232 specification
Serial Control Port connectors:             DB25 F

Operating Temperature         -18o to 55o C (0o to 130o F)
Storage Temperature            -40o to 70o C (-40o to 158o F)
Humidity                                 up to 90% (non-condensing)
Cooling                                  Convection




Technisys Inc
65 Cooper Street
Woodbury NJ 08096


Technisys pn 701395