Ademco NuTech AD2USB flow - no data

I installed a flow to obtain data from a nuTech Ad2USB unit, connected to a serial port:

I had in the beginning some serial read errors because the Nutech software was looking on the port to provide the interface to control the ademco panel. This is solved.

But I have absolutely no data coming from the serial (debug is empty, nothing to parse), whatever I do with the alarm (arm, disarm, check, etc)

Am I forgetting something basic here ?

Is anything actually coming out of the serial port into those nodes ?

In fact no, but should I send something to receive an answer ?

I receive (in other serial communication, in fact serial to modbus 485) info from a modbus device, without doing anything: I harvest the serial-modbus, parse the data and use them accordingly.

But maybe I'm fooled by the serial-rs485 behavior and I missed that I need to send (what ?) strings to the serial (then ad2usb them ademco) to obtain an answer.? I was genuily thinking that playing with the ademco system (arm/disarm) will push data to ad2usb and serial port, but no luck.

Well the serial in node will only show data that arrives at it - so the remote system must send something to start things off. How that happens is down to that remote system. I guess yes you may need to send it something in order to get it to respond - in which case maybe a serial request node would be better - and then inject some message or other - I have no idea what this ademco is so can't help on that side I'm afraid.