Traccar from Wialon IPS without coodinates sets devices at 0,0 position

Hello.
Im using wialon IPS protocol to send to Traccar navigation data. In accordance with the protocol I can send packets without coordinates by using such message (NA;NA;NA;NA; used instead of Lat; N/S;Long;E/W):

250224-061907:--> [Traccar]#L#2.0;XXXXXXXXXX;NA;9831
250224-061907:<-- [Traccar]#AL#1
250224-061907:--> [Traccar]#D#240225;061905;NA;NA;NA;NA;NA;315;NA;0;NA;NA;NA;;NA;rssi:1:28,gnss_status:1:86,channel:1:0,bat_voltage:2:4.062,gnss_status:1:1;9A21
250224-061907:<-- [Traccar]#AD#1

As I see Traccar prases these messages (and set position) at Latitude 0, Longitude 0.
Could you fix it and stay point at last coordinates if packets with NA;NA;NA;NA arrived?

The problem is that you're sending 315 as the course. It will never happen on a real device. You either have all GPS data on none.

Ok. I will test it with all NA and reply you tomorrow.

Could you explain me what I should do to manage "valid" parameter (does it affect to something?)?
I see a snippet of code (WialonProtocolDecoder.java):

        if (parser.hasNext()) {
            int satellites = parser.nextInt(0);
            position.setValid(satellites >= 3);
            position.set(Position.KEY_SATELLITES, satellites);
        }

Sorry I don't know JAVA.

I tried to send to Traccar 0 and 3 instead NA in Sats position. Both cases I got "valid" in "YES" state (also tried to set valid:1:0 directly in parameters part - nothing changed).
If I send ALL data as NA except Time and Date I see that valid is always YES.

#AL#1
250224-184221:--> [Traccar]#D#240225;184220;NA;NA;NA;NA;NA;NA;NA;3;NA;NA;NA;;NA;valid:1:0,rssi:1:31,channel:1:0,battery:2:4.000;8A5E
250224-184221:<-- [Traccar]#AD#1


250224-190221:--> [Traccar]#D#240225;190220;NA;NA;NA;NA;NA;NA;NA;0;NA;NA;NA;;NA;valid:1:0,rssi:1:31,channel:1:0,battery:2:4.000;EB35
250224-190221:<-- [Traccar]#AD#1

Valid is the GPS fix flag.

So, how to send it via wialon IPS? valid:1:0/1 - not working.

Not actual. I've done experiments and know now how it works (valid = coordinates && sat >=3).

Also I checked sending data via IPS D-message with all possible NA in paket after previous valid position fix: device with new invalid data shows in last valid position as expected.
Thank you.