Background: the company's switchboard is FSK caller id pattern, but the switch time is slower than the standard Beijing time, loses 5-10 min, a start is okay, but time grew more and more slow, slow 1 h30min above now, cause the user ext caller id time is always not correct, is not very convenient, because the company this switch is inherited in a company's equipment, so now no technical personnel in the company will maintain time slow problem, so had been continued, so for ext user can online way Ann a converter, such as simple equipment, converts the signal switches issued FSK caller id DTMF? This unit receives the caller id in the signal does not contain the date and time data, the user as long as the date/time on your telephone set can be right, but look at the one treasure, only a few sellers in turn sell DTMF FSK converter, said there was not, in turn, turn DTMF FSK, please the world in a great god, and if there is any support FSK DTMF equipment? Thanks!