English French German Italian Japanese Korean Spanish
V.35 async to sync rate adapter picture

Features / Benefits

  • Interface - Async/Sync RS-232 DB-25 Female, Sync V.35 MR-34 Female
  • Data Rates - Async/Sync is 4.8kbps to 115.2Kbps, Sync is 64kbps or 128Kbps
  • Allows low speed async/sync terminals to access high speed sync circuits
  • Options to force control signals
  • Optional RTS in-band to DCD, DSR or CTS with the data
  • Supports Async or Sync data
  • AC Mains powered 110 or 220 VAC


The RA-64/128K Rate Adapter allows low speed async/sync RS-232 DTE equipment to transmit over a high speed 64k or 128k sync communications link. The RA-64/128k devices are used in pairs, one at each end of the communications link or in multiples as when used in a multi-point or broadcast communications link. The RA-64/128k will support bi-directional or simplex data transmissions.

The RA-64/128k supports async character length of 8, 9, 10 and 11 bits, including the start and stop bit. The asynchronous interface is RS-232 and supports data rates of 4.8k, 9.6k, 19.2k, 38.4k, 57.6k or 115.2k. The synchronous data interface rate must be set at 64k or 128k and will support V.35.

The V.35 data interface will support both the old V.35 (+/-0 .5 volts) or newer V.35 (ITU recommendation V.11) ground to +3.8 volts. A DB-25 male to V.35 male 6 foot adapter cable is required for V.35 termination. The cable should be ordered under part number 712005.

The RA-64/128k has internal switch options to force control signals. Additionally, the user may set RTS to be in-band with the data to DCD, DSR or CTS. This is useful for networks that have no control signals passed.

The RA-64/128k is housed in a sturdy aluminum enclosure and is supplied with an internal linear power supply. The unit has a 110/120 VAC rotary select switch located on the rear of the housing. The unit can operate on standard power found in all countries.

The RA-64/128k has a three year warranty and a 24 hour turnaround on warranty repairs.

V35 async to sync adapter


Application Interconnection of a low speed async/sync terminal or DTE device operating at 4.8k, 9.6k, 19.2k, 38.4k, 57.6k or 115.2k to a synchronous 64k or 128k modem or DCE device
Capacity One terminal(DTE) and one modem(DCE)
Switches Internal Switches for Baud Rate, Character Length, Control Signals, In-Band Control Signals, Crystal Setting
Data Channel Interfaces Async/Sync: RS-232 on DB-25 Female
Sync: V.35 on MR-34 Female
Data Rates RS-232: 4.8k, 9.6k, 19.2k, 38.4k and 57.6k or 115.2k(utilized on 128k only)
Sync: 64K or 128K
Enclosure Metal: Aluminum
Power Source 100-120 to 200-220VAC @10%, 50/60Hz, 0.16/0.08A, external 110/220 volt select switch, IEC Power Inlet, (2) 5mm Fuses
Environmental Operating Temperature....32º to 122º F (0º to 50º C)
Relative Humidity.............5 to 95% Non-Condensing
Altitude............................0 to 10,000 feet
Dimensions Height ....... 1.75 inches (4.44 cm)
Width ........ 7.90 inches (20.07 cm)
Length ....... 9.00 inches (22.86 cm)
Dimensions Standalone Height ....... 1.75 inches (4.44 cm)
Width ........ 9.00 inches (20.86 cm)
Length ...... 9.00 inches (20.86 cm)
Weight 2 pounds (0.91 Kg)
Warranty Three Years, Return To Factory
Regulatory Approvals UL 60950-1:2003, CAN/CSA-C22.2 No. 60950-1:2003FCC Part 15, EN55022:2006, ICES-003, Class A
Ordering Information
Model: RA-64/128k_V35-AC
Part Number: 177000
Description: RS-232 Async/Sync V.35 sync Rate Adapter, AC Powered

Part Number:712005
Description:6 ft.,DB-25 to V.35 adapter cable

1) Operations Manual

For further detailed technical information on this product, contact East Coast Datacom Technical Assistance toll free at (800) 240-7948


Sync2IP: 2-Port Sync or Async to 10/100 LAN Adapter