Battery Mode on 924e Gen3

[socalnet]

We're trying to set the battery-mode on an FXS port of a 924e Gen3 and the command doesn't seem to exist?

924e-gen3(config-fxs 0/1)#battery-mode

% Unrecognized command

The 924e Gen2 seems to have this command ...

924e-gen2(config-fxs 0/24)#battery-mode

auto                   - Automatically switch between high and low battery

                         (default)

high                   - Only use the high battery to feed tip/ring

low                    - Only use the low battery to feed tip/ring

Did it change on the Gen3? We need to set it to "battery-mode high" for a PBX that seems to not be happy with the current voltage/current levels.

[jayh · Accepted solution]

It does seem to have been removed. This was to adjust loop current for long or short loops. Hardware in the Gen. 3 may do it automatically. You might want to verify tip and ring polarity and ensure that the PBX and the TA900 are both grounded to a common ground as this can cause issues. You can set the ring voltage level on the Gen 3 but not the loop current.

[socalnet]

Automatically? Heh, I'd like to set it myself, even when the Gen3 thinks it may know better, I have a old picky PBX that likes high current even on a short loop.

Are you talking about a common ground on the electrical outlet? The Adtran and PBX are fed off the same outlet, so they are "commonly" grounded. Or are you referring to having a ground strap between the Adtran and PBX?

[jayh · Accepted solution]

It's best practice to run a ground from telecommunication devices to a common ground and not rely on the third-wire in the AC cords. There's a ground stud on the back of the TA900 for this purpose and most PBXs also have this provision. It's essential for ground-start trunks and also for detecting ringing in some scenarios. If practical, use the same grounding point as the telco protector at the demarc.