eReadAddressString [LJM User's Guide]
Read a device register that returns a string, specified by address.
Syntax
LJM_ERROR_RETURN LJM_eReadAddressString(
int Handle,
int Address,
char * String)
Parameters
Handle [in]
A device handle. The handle is a connection ID for an active device. Generate a handle with LJM_Open or LJM_OpenS.
Name [in]
The address that specifies the Modbus string-type register to read. Addresses can be found throughout the device datasheet or in the Modbus Map.
String [out]
A string that is updated to contain the result of the read. Must be allocated to size LJM_STRING_ALLOCATION_SIZE
(50
) or greater prior to calling this function.
Returns
LJM errorcodes or 0
for no error.
Remarks
See also LJM_eWriteAddressString. This is a convenience function that uses LJM_eAddresses. Only for use with Modbus registers listed as type LJM_STRING
(98
).
Example
Read the device name.
int LJMError;
// LJM_STRING_ALLOCATION_SIZE is 50
char devName[LJM_STRING_ALLOCATION_SIZE];
// handle comes from LJM_Open()
LJMError = LJM_eReadAddressString(handle, 60500, devName);
if (LJMError != LJME_NOERROR) {
// Deal with error
}
printf ("%s \n", devName);