TELEPHONE EXCHANGE, TELEPHONE SYSTEM AND INTERFACE UNIT

摘要

PROBLEM TO BE SOLVED: To make it easy to narrow down causes of the occurrence of a fault. SOLUTION: An external interface section 115 such as an RS-232C is connected to a CPU that receives/processes information coming from a Caller ID line 20 in an analog front end section, and an external PC 40 or the like is used to directly monitor information not processed coming from the ID line 20, then causes of the occurrence of an error can be narrowed down.