PURPOSE: To provide a terminal equipment which has the ability eliminating the conflict between the local identification number and other numbers by providing an unanswered state detecting means and a circuit establishment answering means which answers the identification number of the detecting circuit establishment polling as an adopted number of its own station to a main station in reply to the detection of the unanswered state.

CONSTITUTION: When a circuit establishment polling is detected on a communication circuit 2, a fact whether the data transmission/reception polling of the same identification number as the circuit establishment polling detected in a step ST101 is confirmed on the circuit 2 or not for only a fixed time in the ST102 and 103. This confirming time is set as a period when the circuit establishment polling is issued by a host computer and accepted by a certain terminal equipment for establishment of a data link, and the processing is switched to another terminal equipment of the host computer after the state monitoring is over. So that the processing is complete for the ST104 and 105 and the larger one of the time needed to return to the ST101 and the time needed to complete the processing of ST104 and 106 is adopted.