Intelligent concentrator for multiple speed data communications systems

A method for detecting non-token-ring devices attempting to gain access to a digital token ring communications network comprising the steps of:

• (a) selecting a timing period;
• (b) counting the number of signal transitions made by data output from the network devices during the timing period;
• and
• (c) generating a valid signal indicating the network devices are token ring devices only if a predetermined number of signal transitions are counted within the timing period.

A circuit arrangement for detecting non-token ring devices attempting to gain access to a token ring communications network comprising:

• a first counter being clocked at a set rate by an internal clock and generating a period signal when a specific count is reached;
• a first gated latch coupled to an output pin of said first counter for latching the period signal;
• a second counter having a reset pin coupled to an output of the first gated latch and a clock pin for receiving signals representing data outputted by one of the network devices;
• and
• a second gated latch having a control input coupled to an output of the first gated latch;
• a data input coupled to an output of said second counter and an output for indicating if a threshold count has been reached during a previous period.