Mega serial reading...itself?

hello, using arduino board controll 4 power supplies used operate underwater rov (remotely operated vehicle). supplies controlled via rs485 network (very similar rs232), , have max13086eepd tranciever connected mega serial2 rx , tx.

data transmission works fine, can activate , de-activate supplies' output change voltage levels without problem.

however, when send comand stt?, tells supply send of it's status information, listen on serial2 , stt? back. @ first thought supplies echoing, discovered serial2.read() returned sent when rx+ , rx- lines supply disconnected transciever.

i know fact supplies trying talk back, can see digital data coming osciloscope. none of seems read software however.

i'll post code here, either doing dumb, or known issue. when code get's loop, says supply adress 7: mv? (what's voltage?) , listens response, should 5 character string, instead mv?

code: [select]



void setup(){

 serial2.begin(19200);
 serial.begin(19200);
 serial.println("code starting");
 
 serial2.println("adr 7");
 delay(100);
 serial2.println("rem 1");
 delay(100);
 serial2.println("out 1");
 delay(100);
 serial2.println("pv 20");
 delay(100);
 
 serial2.println("adr 8");
 delay(100);
 serial2.println("rem 1");
 delay(100);
 serial2.println("out 1");
 delay(100);
 serial2.println("pv 20");
 delay(100);
 serial2.println("adr 7");
 delay(100);
 serial2.flush();
}

void loop(){
 char num = 'q';
 
 serial2.println("mv?");

 delay(2000);

 while(serial2.available() > 0){
   num = serial2.read();
   delay(200);
   serial.print(num);
 }
 serial.println("");

 delay(5000);

}



thank taking time read this, appreciated!

as know, using full-duplex transceiver chip sounds wired half-duplex both di , /re lines both enabled @ same time. loop whatever transmitted receiver.

it looks sketch not using 9-bit address mode available rs485 networks, rather slaves addressed ascii text strings.

can describe how network wired, 2-wire, 4-wire, etc, or link user manual slaves? include how driving de , /re line mega don't see in sketch that.

you're doing dumb.

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