Illegal data value

[GoogleCodeExporter]

1. I upload the Simple Modbus slave example to arduino.
2. Connect arduino uno to computer via max485 and USB to rs485 converter
3. Try to read registers with Modbus poll and Mtester

I receive message "Illegal data value".I am using arduino 1.0.2 on Windows 7 
64bit
?

What does it mean?Where is the problem?
Thanks

Original issue reported on code.google.com by dilie...@gmail.com on 8 Dec 2012 at 10:14

[GoogleCodeExporter]

Hi, I use Mtester & QModbus for all my testing, "Illegal data value" means 
either your starting address is incorrect or you are trying to read too many 
registers at once. Using Mtester the starting address is 1 and the amount of 
registers to read is 9 when referring to the slave example. It includes the 
offset starting address.
When using QModbus the starting address is 0.

Original comment by bester.j...@gmail.com on 28 Dec 2012 at 9:08

[GoogleCodeExporter]

Thanks for replay,
I found my mistake and now I can control arduino via modbus.Now i want to
configurate arduino ethernet as tcp/modbus master and read data from other
arduinos and send data to server whith tcp protocol.Is this possible and
how can I do this.

Original comment by dilie...@gmail.com on 7 Jan 2013 at 8:33

[GoogleCodeExporter]

In addition to Modbus ASCII and RTU there also exist a Modbus/TCP protocol but 
this must be targeted on the TCP layer and adhere to the Modbus/TCP standard 
and is going to be hard work to port.

I would suggest (and maybe this is what you meant :-) that you just set up as 
much packets with different array registers as you need with SimpleModbusMaster 
and then use the array of data as any other data when using the TCP library.

Original comment by bester.j...@gmail.com on 9 Jan 2013 at 8:50

[amittanwar2112]

I Have been using libmodbus rtu pc as master smart energy meter as a slave while sending a read command i'll always get illegal data value repeatedly

[amittanwar2112]

/*

• Copyright © 2008-2014 Stéphane Raimbault stephane.raimbault@gmail.com
• SPDX-License-Identifier: BSD-3-Clause */

include

ifndef _MSC_VER

include

endif

include

include

include

include

//#include "slave.h" /* The goal of this program is to check all major functions of libmodbus:

• write_coil
• read_bits
• write_coils
• write_register
• read_registers
• write_registers

• read_registers

  All these functions are called with random values on a address range defined by the following defines. */

  define LOOP 1

  define ADDRESS_START 0

  define ADDRESS_END 4

/* At each loop, the program works in the range ADDRESS_START to

• ADDRESS_END then ADDRESS_START + 1 to ADDRESS_END and so on. */

int main(int argc,char argv[]) { modbus_t ctx; int rc; int i; // char x[5]; float tab_reg[128]; int code ; //uint16_t command[100]=; ; // int nb_fail; // int nb_loop; // int addr; / RTU / // modbus_rtu_set_serial_mode(ctx);

//code=atoi(argv[1]);
int Slave_ID;

  Slave_ID=atoi(argv[1]);

  code=atoi(argv[2]);

// list(); / printf("Please enter the slave ID: \n");
for(i=22;i<=23;i++) { printf("->Enter ID %d for slave %d: \n",i, i); } /

int c;
FILE *file;
file = fopen("/home/aviconn/opt/openHAB/distribution-1.7.0-runtime/configurations/slave", "r");
if (file) {
while ((c = getc(file)) != EOF)
    putchar(c);
fclose(file);
         } 

printf("\n");
//printf("Please enter the slave ID: ");    

//scanf("%d",&Slave_ID);
/*    if(Slave_ID==22 || Slave_ID==23)
{
  printf ("slave is present");
}
else{
    printf("slave is absent");
}   

/ FILE fp = popen("ls -1 /dev/ttyUSB", "r"); char path[500]; / Read the output a line at a time - output it. */ printf("\n%s\n", "Available USBs are:"); //while (fgets(path, sizeof(path)-1, fp) != NULL) { for (int j=0; fgets(path, sizeof(path)-1, fp) != NULL; ++j) { printf("[%d] %s\n", j, path); }

/ for(int k=0; x[k] != NULL; k++) { printf("%s\n",x[k]); }/ // printf("enter the required USB port "); // gets(x);

/* char a[20]= "/dev/ttyUSB"; char b[1]; scanf("%s", &b); strcat(a,b);

printf("\n-------------------------------------------------------------------------------------------------------------------------\n");

ctx = modbus_new_rtu(a, 9600, 'N', 8, 1);
*/

  ctx = modbus_new_rtu("/dev/ttyUSB0", 9600, 'N', 8, 1);

modbus_set_slave(ctx, Slave_ID);

modbus_set_debug(ctx, TRUE);
modbus_set_error_recovery(ctx,
                          MODBUS_ERROR_RECOVERY_LINK |
                          MODBUS_ERROR_RECOVERY_PROTOCOL);

if (modbus_connect(ctx) == -1) {
    fprintf(stderr, "Connection failed: %s\n",
    modbus_strerror(errno));
    modbus_free(ctx);
    return -1;
}

    if (code==03)
{

    tab_reg[0]=atoi(argv[3]);
tab_reg[1]=atoi(argv[4]);
tab_reg[2]=atoi(argv[5]);
tab_reg[3]=atoi(argv[6]);
tab_reg[4]=atoi(argv[7]);
tab_reg[5]=atoi(argv[8]);
tab_reg[6]=atoi(argv[9]);
tab_reg[7]=atoi(argv[10]);
tab_reg[8]=atoi(argv[11]);
//tab_reg[9]=atoi(argv[12]);
/*tab_reg[10]=atoi(argv[13]);
tab_reg[11]=atoi(argv[14]);
tab_reg[12]=atoi(argv[15]);
tab_reg[13]=atoi(argv[16]);*/

//tab_reg[14]=atoi(argv[17]); //tab_reg[15]=atoi(argv[18]); //tab_reg= {61,73,71,,72,31,00}; //tab_reg[10] //tab_reg[11]

//tab_reg[0]="61 73 6d 5f 71 6b 72 5f 31 00";
    //tab_reg[0]=argv[3];

rc = modbus_read_registers(ctx, 1001, 4, tab_reg);
if (rc == -1) {
    fprintf(stderr, "%s\n", modbus_strerror(errno));
    return -1;
}

for (i=0; i < rc; i++) {
    printf("reg[%d]=%d (0x%X)\n", i, tab_reg[i], tab_reg[i]);
 }

}

// modbus_set_slave(ctx, Slave_ID); if(code==10) { tab_reg[0]=atoi(argv[3]); tab_reg[1]=atoi(argv[4]); tab_reg[2]=atoi(argv[5]); tab_reg[3]=atoi(argv[6]); tab_reg[4]=atoi(argv[7]); tab_reg[5]=atoi(argv[8]); tab_reg[6]=atoi(argv[9]); tab_reg[7]=atoi(argv[10]); tab_reg[8]=atoi(argv[11]); tab_reg[9]=atoi(argv[12]); //tab_reg[10]=atoi(argv[13]) //tab_reg[11]=atoi(argv[14]); rc = modbus_write_registers(ctx, 1000, 20, tab_reg); if (rc == -1) { fprintf(stderr, "%s\n", modbus_strerror(errno)); return -1; }

for (i=0; i < rc; i++) { printf("reg[%d]=%d (0x%X)\n", i, tab_reg[i], tab_reg[i]); } }

modbus_close(ctx); modbus_free(ctx);

return 0;

}