YASKAWA MP920 - Page 287

Appendix C C Language Sample Programs
C.2.1 TCP (When Using Extended MEMOBUS Protocol)
C-12
case 0x06:
//Modify a Single Holding Register Contents
case 0x08:
// Loopback Test
memex_len = 7;
// Extended MEMOBUS Length for Response
sbuf[17] = rbuf[17];//
Send a received data.
sbuf[18] = rbuf[18];//
Send a received data.
sbuf[19] = rbuf[19];//
Send a received data.
sbuf[20] = rbuf[20];//
Send a received data.
break;
case 0x09:
// Read Holding Register Contents (extended)
data_size = (unsigned short)((unsigned char)rbuf[21]) << 8;
data_size += (unsigned short)((unsigned char)rbuf[20]);
data_size *= 2;
// Read data size in bytes
memex_len = data_size + 6;
// Extended MEMOBUS Length for Response
//
data size + 6 bytes (MFC, SFC, CPU No, SPEAR, REG No)
sbuf[17] = 0x00;
// Spare is fixed to 0.
// Sets the number of registers.
sbuf[18] = rbuf[20]; // DataNum(L)
sbuf[19] = rbuf[21]; // DataNum(H)
// Prepares a dummy data.
// Converts then sends the requested word unit data into byte units.
for( i = 0; i < (data_size / 2); i++ )
{
sbuf[20 + 2 * i] = i;
// Set data read from sbuf[20].
}
break;
case 0x0B:
// Write to Holding Register (extended)
memex_len = 8;
// Extended MEMOBUS Length for Response
sbuf[17] = 0x00;
// Spare is fixed to 0.
sbuf[18] = rbuf[18];//
Send a received data.
sbuf[19] = rbuf[19];//
Send a received data.
sbuf[20] = rbuf[20];//
Send a received data.
sbuf[21] = rbuf[21];//
Send a received data.
break;
case 0x10:
// Write to Holding Register (extended)
memex_len = 7;
// Extended MEMOBUS Length for Response
sbuf[17] = rbuf[17];//
Send a received data.
sbuf[18] = rbuf[18];//
Send a received data.
sbuf[19] = rbuf[19];//
Send a received data.
sbuf[20] = rbuf[20];//
Send a received data.
break;
default:
// In this sample program, function code other than the above listed are judged
// as not supported codes and an error response will be returned.
memex_len = 4;
// Extended MEMOBUS Length for Response
sbuf[15] |= 0x80
;// Error response (SFC + 80H)
sbuf[17] = 0x01;
// Error response (SFC error)
}
// Length: From MFC to the end of data
sbuf[12] = (char)(memex_len & 0x00FF);
// Extended MEMOBUS length L
sbuf[13] = (char)((memex_len >> 8) & 0x00FF);
// Extended MEMOBUS length H
/****************************/
/* Preparation of 218 Header */
/**************************/
// Sets the data type.
sbuf[0] = 0x19;
// Extended MEMOBUS (Response)