Welltech ePBX80 V.1.1 - Manual (Page 123)

Welltech Technology Co., Ltd. 123
Figure 7
Step 8: Enter two values on On 1 and Off 1 and On 2 and Off 2 of disconnect 1.
(See figure 8)
Step 9: Click apply and reboot it.
Notice: About more disconnect tone type information. (Such as single
frequency)
Please go to Welltech company web FAQ 
Analyze Disconnect Tone of
Wellgate 2540 to refer it.