ICP DAS
LinPAC-52xx Series XV-Board API User Manual
8
2.2. modbusRequestXV
Description:
This function is used to send a Modbus protocol request in an LP-22xx/52xx system.
Syntax:
[ C ]
int
modbusRequestXV(char cPort, char cFunction, WORD wAddr, WORD wCount,
char szBuf, WORD wBufLen)
Parameters:
cPort:
[Input] The number of the COM port for the XV-Board. 1=COM1=/dev/ttyO1.
cFunction: [Input]
The
Modbus
RTU protocol function code.
wAddr:
[Input]
The
channel
address.
Note
: Input the channel address mapping in
decimal
format.
wCount:
[Input] The number of channels.
szBuf[ ]:
[Input
/
Output] Used to set or read back the value from a function code.
wBufLen:
[Input] The length of the szBuf[ ].
Return Values:
0: The function was successfully processed.
Other: The processing failed.
Refer to Chapter 3: “
” for details of other returned values.
