FEATURES

• MTM-20 is an extended range, 4-wire modem operating at data rates of 32 or 64 kbps. It is optimized for metropolitan applications where the distances are too long or the operating conditions too poor for standard short-range modems.

• The MTM-20 sync modem provides full duplex data transfer over unconditioned, 4-wire leased lines. It uses an adaptive equalizer and QAM modulation to achieve reliable performance, even over poor quality lines. At 64 kbps, over 24 AWG unconditioned lines, MTM-20 has a range of
  14 km (9.3 miles) and over
  19 AWG lines a range of up to
  32 km (20 miles).

• MTM-20 supports a wide range of digital interfaces:
  - V.24/RS-232
  - V.35
  - V.36/RS-449
  - RS-530
  - G.703 codirectional (64 kbps)
  - X.21 and a built-in Ethernet bridge.

• Transmit timing is provided internally or recovered from the receive signal. Alternatively, the transmit timing can be derived externally from the digital interface, enabling tail-end applications. Receive timing is generated from the receive signal. The transmit level is selectable in 3 dB increments, over the range of 0 to -12 dBm.

• MTM-20 features V.54 diagnostics for performing local analog loopback and local and remote digital loopbacks. The loopbacks can be activated either from the front panel or by control signals via the digital interface.

• MTM-20 can perform a Bit Error Test on the link, using an internal pseudo-random test pattern. A front panel signal quality (SQ) LED flashes when a bit error is detected. In addition, line quality is tested online, without interruption or interference to data transmission.

• MTM-20 is available as a standalone unit or as a rack-mount card for the ASM-MN-214 19" modem rack. Special hardware is available for mounting one or two standalone units in a 19" rack.

ORDERING

MTM-20SA/115/530
MTM-20SA/115/703TB
MTM-20SA/115/UTP
MTM-20SA/115/V24
MTM-20SA/115/V35
MTM-20SA/115/V36
MTM-20SA/230/530
MTM-20SA/230/G703
MTM-20SA/230/V24
MTM-20SA/230/V35

APPLICATIONS