一、什么是集团电话? 集团电话就是一组分机电话共用一对或几对局用外线的通信终端设备。如4个分机共用一对外线,称为一拖四,同理有“二拖八”、“四拖十六”等等,通常外线对分机是并联的,例如二拖八,则每只分机有两个专门开关,两个指示灯,外线和各分机开关及指示灯并联,再连接分机的振铃器。连接振铃器时,有隔离电路,以免两对外线相互影响。当外线呼入时,各分机的振铃器响,指示灯闪亮。此时任一分机按下开关,便可接听,指示灯即为常亮。如接听时需保密,要另加保密措施。限 First, what is the PBX? PBX is a group of extension telephone share one or several pairs with the outside office of the communication terminal equipment. Such as four extensions share a pair of outside lines, called a drag four, the same reason “two drag eight”, “four drag sixteen” and so on, usually outside the extension is parallel, such as two drag eight, then each extension There are two special switches, two indicator lights, the outside line and the extension switch and indicator light in parallel, then connect the extension ringer. When connecting the ringer, there is an isolation circuit to prevent the two pairs of outside lines from interacting with each other. When the outside incoming, the extension ringer, light flashing. At this point any extension press the switch, you can answer, the indicator is always on. Such as answering the need to keep confidential, to be additional security measures. limit