Moxa Technologies NE-4100 - Manual (Page 82)

NE-4100 Series User’s Manual DIO Commands
C-2
//define DIO Packet format
//Used for Command and ACK packet
typedef struct _DIO_Packet_Struct {
DIOHeaderStruct
header;
char data[255];
} DIOPacketStruct, *pDIOPacketStruct;
Command Code Usage
1. Reading Single DIO
Parameters:
Command code: 1(hex)
Version: 2(hex)
Command Status: doesn’t matter
Length of data: 1(hex), represents one byte.
data[0]: Fill in the number of the DIO you wish to access. The DIO number starts from 0(hex).
Return:
Command Status: Check the Command Status code on the previous page.
Length of data: 3(hex). Must be 3 bytes of return code in this mode.
data[0]: The number of the DIO you wish to access.
data[1]: DIO mode(hex), 0 for IN, 1 for OUT
data[2]: DIO status(hex), 0 for LOW, 1 for HIGH
C code example:
BOOL ReadSingleDIO(int port, int *mode, int *status)
{
DIOPacketStruct packet;
packet.header.command = 1; // read single DIO command
packet.header.version = 2; // DIO protocol version
packet.header.length = 1; // data length
packet.data[0] = (char)port; // Number of the DIO
send(SocketFd, (char *)&packet, sizeof(DIOHeaderStruct)+1, 0); //Send TCP Packet
// Process the returned data here.
return TRUE;
}
2. Writing a Single DIO
Parameters:
Command code: 2(hex)
Version: 2(hex)
Command Status: doesn’t matter
Length of data: 3(hex); represents three bytes.
data[0]: The number of the DIO you wish to access.
data[1]: DIO mode(hex), 0 for IN, 1 for OUT
data[2]: DIO status(hex), 0 for LOW, 1 for HIGH
Return:
Command Status: Check the Command Status code on the previous page.
Length of data: 3(hex). Must be 3 bytes of return code in this mode.
data[0]: The number of the DIO you wish to access.
data[1]: DIO mode(hex), 0 for IN, 1 for OUT
data[2]: DIO status(hex), 0 for LOW, 1 for HIGH