RAD SRM-31A Miniature Multirate 2-Wire Modems 

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RAD SRM-31A Miniature Multirate 2-Wire Modems 


  • SRM-31A is an Asynchronous Short Range Modem that operates full duplex over 2-wire unconditioned lines (twisted pair) at selectable rates from 1.2 kbps to 115.2 kbps.
  • SRM-31A uses I-DSL technology and 2B1Q line coding. It provides an operating range of up to 8 km, independent of the data rate. An adaptive equalizer provides noise immunity and high performance, over mixed gauge or multi-pair cables. SRM-31A can pass two control signals end-to-end with no data transmission interference.
  • SRM-31A is a miniature version of ASM-31. External switches on the bottom of the unit enable easy configuration of the product. Five LED indicators show the status of the unit. The modem requires an external power source via an AC adapter (see Ordering).
  • SRM-31A can operate opposite ASM-31, ASMi-31, and the HS-U module of Megaplex-2000 and Megaplex-2100. SRM-31A can be configured remotely, and diagnostics can be activated from the other end.
  • SRM-31A features diagnostic capabilities that include implementation of local and remote loopbacks.


  • Asynchronous
  • 2-wire full duplex
  • Transmission range up to 8 km
  • I-DSL technology and 2B1Q line coding
  • Operates opposite ASM-31, ASMi-31, and HS-U modules of MP-2000 and MP-2100
  • V.24/RS.232 DTE interface
  • Diagnostic loops according to ITU V.54
  • Selectable data rates:
    1.2 kbps - 115.2 kbps
  • LED indicators
  • Configuration download option when working opposite ASMi-31

2-wire Short Range Async Modem

+ Specify power supply:
(Default is with no power supply)
115 for 115 VAC
230 for 230 VAC




RAD Products

For discount pricing on RAD Data Communications
email us at sales@data-connect.com
or call 301-924-7400