English French German Italian Japanese Korean Spanish

Features / Benefits

  • Interface Modules Available for - V.35 RS-422/449, RS-530, RS-232 or X.21
  • User Selectable buffer sizes of 1,024, 2,048, 4,096 and 8,192 bits
  • Data Rates - Synchronous to 2.048Mbps
  • Timing - accepts external timing from attached DCE
  • Rackmount or Standalone
  • 110/220VAC switch selectable


The RDS-TCB Tail-Circuit Buffer is designed to provide selectable bi-directional buffering between two data circuits that are operating at nominally the same clock rate and are capable of providing clocking as a DCE. In such cases, the timing of the two circuits is not locked to the same timing source, or may be allowed to deviate from a com-mon timing source for a length of time. The RDS-TCB meets this need by pro-viding selectable amounts of bi-directional memory from 1,024 bits up to 8,192 bits and supports synchronous clock rates up to 2.048 Mbps.

The data memory is based upon a self-centering FIFO buffer. Upon power-on, a reset, or a prior buffer underrun or over-flow, the buffer will accept and hold all input data until the buffer is half full. At that point, the buffer will be released to output the first data received and will continue input and output through the FIFO at the rate determined by the input and output clocks. Differences in clock-ing rates on the two interfaces will result in the amount of data queued in the buffer changing over time. As long as the amount queued does not decrease to zero (FIFO empty) or reach the maxi-mum memory value selected (FIFO full), then data output will correctly match data input, with a delay that is a function of the length of the queue and the bit clock rate.

An additional option controls whether certain control signals, namely DCD on the input side to RTS on the output side, are passed directly through the buffer without delay, or through the buffer memory with the same delay as data.

The RDS-TCB is housed in a sturdy metal standalone or Rackmount enclo-sure and operates on 110/220VAC.

The unit has a three-year warranty and a 24-hour turnaround on warranty repairs.



Application Elastic data buffering (FIFO memory) function between two systems having nominally equivalent clocking rates
Buffer Size/Function User Selectable: 1024, 2048, 4096 and 8192 bits
Control Signal Options User selectable DCD to RTS buffer by-pass or enable
Capacity Two (2) DCE devices, one for each port
Data Rates Up to 2.048Mbps
Data Channel Interfaces Available in V.35, RS-530, RS-422/449, RS-232 or X.21
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%
Altitude............................0 to 10,000 feet
Dimensions Height ....... 1.75 inches (4.44 cm)
Width ........ 17.00 inches (43.18 cm)
Length ....... 9.00 inches (22.86 cm)
Weight 2 pounds (0.914Kg)
Warranty Three Years, Return to Factory
Ordering Information: Part Number: 160000
Model: RDS-STB
Description: Tail Circuit Buffer
Interfaces Available:
V.35, PT# 129010
RS-530, PT# 129011
RS-422/449, PT# 129012
X.21, PT# 129013
RS-232, PT# 129014
Included with each unit: 1) Operations Manual
2) U.S.A. Grounded Power Cord, Part # 713015
3) Optional Power Cords
A) United Kingdom, Part # 713016
B) Continental Europe, Part # 713017
C) Other: Specify Country on Purchase Order
Regulatory Approvals CE Approved, RoHS Compliant
Optional Accessories 1) Spare Data Center Fuses
A) 160ma Fuse, Qty (2) Part # 714000
B) 80ma Fuse, Qty (2) Part # 714001