SITL send analog value to PIN

Hallo

In real world, i have a analog-sensor connect to PINx.
Howto simulate to send analog_voltage to PINx in SITL with sim_vehicle?

With mavlink I can send msg, but apparently not send a value to PINx.

One way could be via serial port, like:
echo $data > $tty1 ----- socat ----- sim_vehicle $tty2

i have found [1] but no working example

One way could be via telemetry-port 5762
python $script --connect 127.0.0.1:5761 ----- sim_vehicle:5762

i have found many scripts to send mavlink-msg, but no script to send a value to PINx.

Does anyone have a link with an example?

regards hans

[1] Simulating a serial device with SITL - #2 by andriots