Any Port to any Port Switch

Product Picture
  • Connects multiple inputs to multiple outputs
  • Up to a 4 megabyte buffer
  • Combined automatic and code activated switching functions


MasterSwitch is a comprehensive data switch for interconnected computers and peripherals using the common serial (RS232) and parallel (Centronics) interfaces. The switch accepts over 20 commands for controlling the flow of data. It may also be set to control data automatically, or be managed with interactive on-screen menus. Menus for configuration, port contention and access, and job control are featured, along with advanced queue system controls for access and prioritization of multiple inputs and outputs. This switch is used in a wide variety of applications, including office automation, CAD/CAM, machine control, data collection, data communications, telecommunications, retail point-of-sale, and more.

MasterSwitch is produced in 3 custom models:

  • MS-Series – 5 or 9 ports, all serial, all parallel, or mixed serial and parallel
  • U-Series – 3, 6, or 9 ports, each port programmable as serial or parallel, input or output
  • N-Series – 4, 8, 12, or 16 serial ports and 1 parallel port, supports file transfer at 115.2K


Dimensions (W x D x H) 10.5" x 5" x 3.9" (267 x 127 x 99 mm)
Weight 8 lb (3.6 kg)
Power 90-240 VAC 50-60Hz External adapter, 17 VAC CT, 700 ma 10W
Distance RS232: 100 feet (30m)Parallel: 25 feet (7.6m)
Connectors MS series serial: DB25FMS series parallel: Centronics 36FMSU/MSN series serial: RJ45 jackMSU/MSN series parallel: DB25FPower: DIN5
Controls Unit power: Green LEDBuffer/status: 8 red LEDsStatus: Red LEDs Data, Busy, BufferLED control: Advance/select push-buttons
Environment Operating temperature: 32°F–131°F (0°C–55°C)Storage temperature: -13°F–140°F (-25°C–60°C)Relative humidity: 5%–80%, non-condensing


Masterswitch MS series
MS-5S5 Serial Ports, DB25F
MS-5P5 Parallel Ports, Centronics 36F
MS-7S2P7 Serial and 2 Parallel Ports, DB25F/Centronics 36F
MS-9S9 Serial Ports, DB25F
MS-9P9 Parallel Ports, Centronics 36F
Masterswitch MSU series
MSU-3SP3 Programmable Serial or Parallel Ports, 3 RJ11-45 and 3 DB25F
MSU-6SP6 Programmable Serial or Parallel Ports, 6 RJ11-45 and 6 DB25F
MSU-9SP9 Programmable Serial or Parallel Ports, 9 RJ11-45 and 9 DB25F
Masterswitch MSN series
MSN-4S1P4 Serial and 1 Parallel Port, 4 RJ45 and 1 DB25F
MSN-8S1P8 Serial and 1 Parallel Port, 8 RJ45 and 1 DB25F
MSN-12S1P12 Serial and 1 Parallel Port, 12 RJ45 and 1 DB25F
MSN-16S1P16 Serial and 1 Parallel Port, 16 RJ45 and 1 DB25F
Serial cables
CAB-ATRSnnnCable, PC to Switch, DB9F to DB25M
CAB-PCRSnnnCable, PC to Switch, DB25F to DB25M
CAB-PRSnnnCable, Serial Printer to Switch, DB25M to DB25M
CAB-04RJnnnCable, 4 Conductor, RJ11 (M-M)
CAB-06RJnnnCable, 6 Conductor, RJ12 (M-M)
CAB-08RJnnnCable, 8 Conductor, RJ45 (M-M)
ACC-ATRXPC serial port to Switch Modular Adapter, DB9F-RJ11
ACC-PCRXPC serial port to Switch Modular Adapter, DB25F-RJ11
ACC-PRRXSwitch to Serial Printer Modular Adapter, DB25M-RJ11
ACC-MORXSwitch to Modem Modular Adapter, DB25M-RJ11
/45RJ45 Option for Modular Adapters
Parallel cables
CAB-IBMPnnnCable, PC to Switch Parallel Cable, DB25M-Centronics C36M
CAB-PMMnnnCable, Switch to Printer Parallel Cable, Centronics C36 (M-M)
CAB-SMMnnnCable, All lines straight thru, DB25M to DB25M
CAB-SMFnnnCable, All lines straight thru, DB25M to DB25F
CAB-IBMPnnn/SCSuperCable, PC to Switch Extended Distance Parallel Cable, DB25M-Centronics C36M
CAB-SMMnnn/SCSuperCable, PC to Switch Extended Distance Parallel Cable, DB25 (M-M)
SW-MN3/4Masternet software 3.5" Diskettes, 4 User Pack
RM-MP/xxRack Mount kit, 3U Chassis, (xx = 19", 23", or 24")
nnn = cable length in feet


Datasheet • MasterSwitch PDF
Manual • MasterSwitch • Installation and Operation PDF