Mitsubishi Electric FR-CC2-P, Instruction Manual, Page: 127 / 184

(N) Operation via communication and its settings
126
PARAMETER
 Instructions for the program
• When data from the computer has any error, the converter unit does not accept that data. Hence, in the user program,
always insert a retry program for data error.
• All data communication, for example, monitoring, are started when the computer gives a communication request. The
converter unit does not return any data without the computer's request. Hence, design the program so that the computer
gives a data read request for monitoring, etc. as required.
• Program example) Writing "0" in Pr.57
Microsoft
®
Visual C++
®
(Ver. 6.0) programming example
#include <stdio.h>
#include <windows.h>
void main(void){
HANDLE hCom; // Communication handle
DCB hDcb; // Structure for setting communication settings
COMMTIMEOUTS hTim; // Structure for setting timeouts
char szTx[0x10]; // Send buffer
char szRx[0x10]; // Receive buffer
char szCommand[0x10];// Command
int nTx,nRx; // For storing buffer size
int nSum; // For calculating sum code
BOOL bRet;
int nRet;
int i;
//

Open COM1 port

hCom = CreateFile("COM1", (GENERIC_READ | GENERIC_WRITE), 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
if(hCom != NULL) {
//

Set COM1 port communication

GetCommState(hCom,&hDcb); // Get current communication information
hDcb.DCBlength = sizeof(DCB); // Structure size setting
hDcb.BaudRate = 19200; // Communication speed = 19200 bps
hDcb.ByteSize = 8; // Data length = 8 bits
hDcb.Parity = 2; // Even parity
hDcb.StopBits = 2; // Stop bit = 2 bits
bRet = SetCommState(hCom,&hDcb); // Setting of changed communication information
if(bRet == TRUE) {
//

Set COM1 port timeout

GetCommTimeouts(hCom,&hTim); // Get current timeout values
hTim.WriteTotalTimeoutConstant = 1000; // Write timeout 1 second
hTim.ReadTotalTimeoutConstant = 1000; // Read timeout 1 second
SetCommTimeouts(hCom,&hTim); // Setting of changed timeout values
//

Setting a command to write "0" in Pr.57 of the station number 1 converter unit

sprintf(szCommand,"01B910000"); // Send data (Parameter write)
nTx = strlen(szCommand); // Send data size
//

Generate sum code

nSum = 0; // Initialize sum data
for(i = 0;i < nTx;i++) {
nSum += szCommand[i]; // Calculate sum code
nSum &= (0xff); // Mask data
}
//

Generate send data

memset(szTx,0,sizeof(szTx)); // Initialize send buffer
memset(szRx,0,sizeof(szRx)); // Initialize receive buffer
sprintf(szTx,"\5%s%02X",szCommand,nSum);// ENQ code + send data + sum code
nTx = 1 + nTx + 2;
// Number of ENQ codes + number of send data + number of sum codes
nRet = WriteFile(hCom,szTx,nTx,&nTx,NULL);
//

Send

if(nRet != 0) {
nRet = ReadFile(hCom,szRx,sizeof(szRx),&nRx,NULL);
//

Receive

if(nRet != 0) {
//

Display receive data

for(i = 0;i < nRx;i++) {
printf("%02X ",(BYTE)szRx[i]);// Output received data to console
// Display ASCII code in Hexadecimal' In case of 0', "30" is displayed.
}
printf("\n\r");
}
}
}
CloseHandle(hCom);
// Close communication port
}
}