Calling system is a device which is connected with telephone line.The users can press the remote control toactivate host panel

1 Dialer can work when switching the power polarity of subscriber line normally.

2 Dialer can work under the condition of 0 ~ 5km in the subscriber line normally.

3 Dialer can meet the request of telephone dialing when automatically DTMF dial-up .

74Dialer' functions can't interfere the work of telephone nets and telephone.