Portsdown 4 PTT Input

[g4hiz]

Hi all,
Does the Portsdown 4 have a PTT Input (ie force transmit TV by hardware input) ? If so, what sense of voltage is required for 'active' and is a menu set-up required?

Edit

For the Portsdown4, a PTT function is available using GPIO pin 12: transmit = 3V3, non-transmit = 0V (pull-up to 3V3 supply suffices).
However in order to use this, the P4 has to be accessed via the network console mode and the following setup done:

Menu
5. System
1. Autostart
select 'Keyed-Tx-boot'
Then reboot.
Once this has been done, the transmit parameters will be those previously setup using the touch-screen, with no further changes possible until you leave this mode, ie return to 'screen start' under autostart via the console as the touch-screen is inactive during the keyed-Tx-boot mode.

Jen