YASKAWA MP920 - Page 280

C.1 Sample Programs for Master Station
C-5
C
// Sets the reference number.
sbuf[18] = 0x00;
// Adr(L) leading address: MW0
sbuf[19] = 0x00;
// Adr(H)
// Sets the number of registers.
sbuf[20] = 0x0A;
// Reads 10 words from the DataNum(L) leading address.
sbuf[21] = 0x00;
// DataNum(H)
}
// Checks the response data.
int chk_rsp_data( int rlen )
{
int rc;
rc = 0;
// Checks the total length of data.
if ( rlen != 40 )
// 40-byte response for 10-word read out
// ((218 header (12 bytes) + MEMOBUS data (28 bytes))
{
rc = -1;
return( rc );
}
// Checks the packet type.
if ( rbuf[0] != 0x19 )
// Not the MEMOBUS response
{
rc = -2;
return( rc );
}
// Checks the serial number.
if ( sbuf[1] != rbuf[1] )
// Does not agree with the command serial number.
{
rc = -3;
return( rc );
}
// Checks the length of the total data in the message.
if (( rbuf[6] != 0x28 ) && (rbuf[7] !=0x00))
// 40 bytes = 218 header (12 bytes) + MEMOBUS data (28 bytes)
{
rc = -4;
return( rc );
}
// Checks the MEMOBUS data length.
if (( rbuf[12] != 0x1A ) || (rbuf[13] != 0x00))
// 26 bytes
{
rc = -5;
return( rc );
}
// Checks the MFC.
if ( rbuf[14] != 0x20 )
// MFC is fixed to 0x20.
{
rc = -6;
return( rc );
}
// Checks the SFC.
if ( rbuf[15] != 0x09 )
// SFC is 0x09 (Read Holding Register Contents).
{
rc = -7;
return( rc );
}