Figure 13: Ports Config Page; Figure 14: Acim Settings - Grandstream Networks UCM6 Series Manual

2. Users can select their country under FXO Opermode to set the On Hook Speed, Ringer Impedance,
Ringer Threshold, Current Limiting, TIP/RING voltage adjustment, Minimum Operational Loop Current,
and AC Impedance as predefined for your country's analog line characteristics.
Note that different countries often have different standards for impedance. Impedance can also depend
on PSTN provider/CO switches and used wires in the same country.
3. Click on under Options next to FXO Ports.
4. Users can manually enter the ACIM settings by selecting the value from dropdown list for each port. Or
users could choose the detect option (either ERL or Pr) then click on "Detect" to automatically detect
the ACIM value. The detecting value will be automatically filled into the settings.
5. Click "Update" to apply the detected ACIM value.
Note: After setting the AC impedance for the connected line to the FXO Port, and notice that audio gains are
still low. Users can increase manually Rx/Tx gains for the Receiving/Transmitting channel of the analog FXO
port. The Rx/Tx audio gains settings can be configured by editing the analog trunk from PBXBasic/Call
RoutesAnalog Trunks. The valid range is from -13.5 (dB) to +12.0 (dB). The default setting is 0

Figure 13: Ports Config Page

Figure 14: ACIM Settings

UCM6XXX Analog Trunks Guide
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