How to retrieve ascii characters from modbus registers?

Twenty ascii characters are in Ten Modbus Registers.  Data in modbus registers is stored in little-endian.  Another words, Most Significant Byte(MSB) is farthest to the right (or last) and the Least Significant Byte(LSB) is farthest to the left (or first).

Example:  "Designate" is stored as follows in modbus registers:

Modbus Register 1:    e    D
Modbus Register 2:    i      s
Modbus Register 3:    n    g

unsigned short response_buffer[128];

/* The data in respone_buffer array should appear as follows:
response_buffer[0] = 'e'
response_buffer[1] = 'D'
response_buffer[2] = 'i'
response_buffer[3] = 's'
response_buffer[4] = 'n'
response_buffer[5] = 'g'                            */

/* Does following code retrieve the string properly  ?  Can this code be improved ?    */
char sco1[20];

for (short    i   =   0;     i    <    10;    i++)
   sco1 [ i ]  =   ( char )  ( ( response_buffer[  i  ]    &    0xFF);
   sco1 [ i ] =   ( char )  ( ( response_buffer [  i  ]    >>  8)  &   0xFF );
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Your index to response_buffer is going to be off

Try something like this:
for( short i=0; i < 5; i++)
    sco1[ i*2 ] = response_buffer[i] & 0xFF;
    sco1[ i*2+1 ] = (response_buffer[i] >> 8);

Open in new window

int i=0;
int j=0;
while( i < 5 )
    sco1[ i++ ] = response_buffer[ j ] & 0xFF;
    sco1[ i++ ] = response_buffer[ j++ ] >> 8;

Open in new window


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