@yveaux Thank you man so much. I wrote topics on gateway's github, here in cotroller section, OH forum and no one knows how to fix that. I cut jumper on RESET EN and it works. TY!

@mfalkvidd I do not find any information sending by gateway to restart arduino. It looks like that:

[log] system start
[log] some relays state changed from null to ON (restored states)
[log] some relays state changed from null to OFF
[log] MySensors bridge is changed from OFFLINE (COMMUNICATION_ERROR)  to OFFLINE
[log] MySensors bridge is changed from OFFLINE (COMMUNICATION_ERROR)  to OFFLINE
[log] MySensors bridge is changed from OFFLINE to ONLINE (finnaly)
[log] all relays changed from OFFLINE to ONLINE

And then arduino restarting. So if i restart OH, arduino keep states until it connect again.

@Yveaux How can i do that?

Arduino is restarting after connect to controler (Serial Gateway - OpenHab). But this is not gateway issue. I think it is quite natural, because arduino had to run presentation, but I wondering is it possible to not restarting arduino? It is very important because i have to controll critical relays by it. And i wont turn it off after gateway restart by any reason.

Thanks. I have just made persist. Looks like that:
config:

# configure specific rrd properties for given items in this file.
# please refer to the documentation available at
# https://www.openhab.org/addons/persistence/rrd4j/
#
# default_numeric and default_other are internally defined defnames and are used as
# defaults when no other defname applies

relpols.def=GAUGE,60,U,U,30
relpols.archives=LAST,0.5,1,365:LAST,0.5,7,300
relpols.items= relay_leda, relay_ledb, relay_ledc, ... , relay_custom5

persist:

Strategies {
    // for rrd charts, we need a cron strategy
    everyMinute : "0 * * * * ?"
}

Items {
    // persist items on every change and every minute
    relay_leda, relay_ledb, ... , relay_custom4, relay_custom5 : strategy = everyChange, everyMinute, restoreOnStartup
}

And it looks quite good. Because after restart, states are restored, but it looks like MySensors are not connected in time. And logs looks like (pseudocode):

[log] system start
[log] some relays state changed from null to ON (restored states)
[log] some relays state changed from null to OFF
[log] MySensors bridge is changed from OFFLINE (COMMUNICATION_ERROR)  to OFFLINE
[log] MySensors bridge is changed from OFFLINE (COMMUNICATION_ERROR)  to OFFLINE
[log] MySensors bridge is changed from OFFLINE to ONLINE (finnaly)
[log] all relays changed from OFFLINE to ONLINE

and then all relays are turning OFF (physicaly) but in OH they have god states. For example relay_ao1 is physicaly off but in OH it is on, so to turn it ON i have to click it 2 time (first time it is switching to OFF).

Any idea to fix it?

edit:
Now i think arduino is restarting after it connect with OH. Can it be true?

Hi. I connect Arduino with MySensors to server machine with linux by serial gateway. Everything is working fine, but when I restart OH process, or machine, all relays are turning off. When i had only lights it wan snot big problem. But now i have some important things that i really won't turning off. Is there possibility to keep relays status when OH is restarting?

My codes:
things

Bridge mysensors:bridge-ser:gateway3 "Gateway Przekaźniki RelPol" [ serialPort="/dev/ttyACM4", sendDelay=50, networkSanCheckEnabled=true ]
{
  light relay_0 'przekaźnik_00' [ nodeId=0, childId=0 ]
  light relay_1 'przekaźnik_01' [ nodeId=0, childId=1 ]
  light relay_2 'przekaźnik_02' [ nodeId=0, childId=2 ]
  light relay_3 'przekaźnik_03' [ nodeId=0, childId=3 ]
  light relay_4 'przekaźnik_04' [ nodeId=0, childId=4 ]
  light relay_5 'przekaźnik_05' [ nodeId=0, childId=5 ]
}

items

Switch relay_0 "stan" (relpols) { channel="mysensors:light:gateway3:relay_0:status" }
Switch relay_1 "stan" (relpols) { channel="mysensors:light:gateway3:relay_1:status" }
Switch relay_2 "stan" (relpols) { channel="mysensors:light:gateway3:relay_2:status" }
Switch relay_3 "stan" (relpols) { channel="mysensors:light:gateway3:relay_3:status" }
Switch relay_4 "stan" (relpols) { channel="mysensors:light:gateway3:relay_4:status" }
Switch relay_5 "stan" (relpols) { channel="mysensors:light:gateway3:relay_5:status" }

arduino

// Enable debug prints to serial monitor
#define MY_DEBUG


// Enable and select radio type attached
//#define MY_RADIO_RF24
//#define MY_RADIO_NRF5_ESB
//#define MY_RADIO_RFM69
//#define MY_RADIO_RFM95

// Set LOW transmit power level as default, if you have an amplified NRF-module and
// power your radio separately with a good regulator you can turn up PA level.
//#define MY_RF24_PA_LEVEL RF24_PA_LOW

// Enable serial gateway
#define MY_GATEWAY_SERIAL

// Define a lower baud rate for Arduinos running on 8 MHz (Arduino Pro Mini 3.3V & SenseBender)
#if F_CPU == 8000000L
#define MY_BAUD_RATE 38400
#endif

// Enable inclusion mode
#define MY_INCLUSION_MODE_FEATURE
// Enable Inclusion mode button on gateway
//#define MY_INCLUSION_BUTTON_FEATURE

// Inverses behavior of inclusion button (if using external pullup)
//#define MY_INCLUSION_BUTTON_EXTERNAL_PULLUP

// Set inclusion mode duration (in seconds)
#define MY_INCLUSION_MODE_DURATION 60
// Digital pin used for inclusion mode button
//#define MY_INCLUSION_MODE_BUTTON_PIN  3

// Set blinking period
#define MY_DEFAULT_LED_BLINK_PERIOD 300

#define MY_NODE_ID 1

// Inverses the behavior of leds
//#define MY_WITH_LEDS_BLINKING_INVERSE

// Flash leds on rx/tx/err
// Uncomment to override default HW configurations
#define MY_DEFAULT_ERR_LED_PIN 4  // Error led pin
#define MY_DEFAULT_RX_LED_PIN  6  // Receive led pin
#define MY_DEFAULT_TX_LED_PIN  5  // the PCB, on board LED

#include <MySensors.h>

class Relay {
  const int pin;
  int state;

  public:
    Relay(int attachTo) :
      pin(attachTo)
    {
    }

    void setup() {
      pinMode(pin, OUTPUT);
    }
    void on() {
      state = 1;
    }
    void off() {
      state = 0;
    }
    void setState() {
      digitalWrite(pin, state);
    }
};


Relay relay0(8);
Relay relay1(9);
Relay relay2(10);
Relay relay3(11);
Relay relay4(12);


Relay relays[] = {relay0, relay1, relay2, relay3, relay4,};

void presentation () {
  // Send the sketch version information to the gateway and Controller
  sendSketchInfo("relays", "0.4");

  for(int i = 0; i < 5; i++){
    present(i, S_BINARY);
  }
}

void setup()
{
  Serial.begin(115200);

	presentation();

  for(int i = 0; i < 5; i++){
    relays[i].setup();
  }
}

void loop()
{
  for(int i = 0; i < 5; i++){
    relays[i].setState();
  }
  wait(20);
}

void receive(const MyMessage &message) {
  // We only expect one type of message from controller. But we better check anyway.
    if(message.type==V_LIGHT && message.getInt() == 0){
      relays[(message.sensor)].off();
    }
    if(message.type==V_LIGHT && message.getInt() == 1){
      relays[(message.sensor)].on();
    }
}