Allied Telesyn Centrecom MX20T

Allied Telesyn Centrecom MX20T ... to the workstation, bringing thin Ethernet or Unshielded Twisted Pair (UTP) wiring directly to the workstation. With UTP and inexpensive coax network media, distances up to 100 meters between workstations can be supported using UTP, and up to 185 meters using coax. On all models Signal Quality Error (SQE)/Heartbeat test can easily be enabled or disabled via an externally accessible switch. Additionally, all models have integral jabber lock-up prevention circuitry and a loopback function. This function emulates coaxial media where transmitted packets are looped back to the receive side. Local Area Network (LAN) controllers can use the loopback feature to determine if a Media Attachment Unit (MAU) is connected and operational.

The AT-MX20T, AT-210T and AT-210TS transceivers incorporate functions that offer improved network reliability for workstations. The 10Base-T link integrity test function provides a continuous test of the connection to the multiport repeater. A test pulse is periodically transmitted and expected at the companion transceiver's receive side. If the pulse is not seen on the receive side, the transceiver is placed into link test fail mode. Normal operation of the transmit side is inhibited and the "Link" LED is turned off. Normal operation is resumed when the link is re-established by the reception of a valid packet or two valid link pulses.