Rockwell-automation 1747-PCIS API Software - Open Controller Manual de usuario descargar pdf (Pagina 140)

Publication 1747-UM002A-US-P - June 2000

6-80 Library of Routines

Considerations:

Supported in the DOS API library and the Windows NT API library

Example:

HANDLE Handle;

WORD outputdata[2];

int retcode;

outputdata[0] = 0x55AA;

outputdata[1] = 0xAA55;

retcode = OC_WriteOutputImage( Handle, NULL, 6, 0, 2,

outputdata );

OC_WriteSRAM

OC_WriteSRAM wires data to the battery-backed user memory

Syntax:

int OC_WriteSRAM(HANDLE Handle, BYTE*bufptr,

DWORD offset, DWORD length);

Description:

The battery-backed memory may be used to store important data that

needs to be preserved in the event of a power failure. The size of the

available memory in bytes may be obtained using OC_GetDeviceInfo.

handle must be a valid handle returned from OC_OpenScanner.

bufptr points to the data to be written. offset specifies the offset

within the memroy to begin writing. length specifiies the number of

bytes to be written.

offset

length

points past the end of the memory, no bytes

will be written and ERR_OCPRAM will be returned.

IMPORTANT

It is recommended that the integrity of data stored in

the user memory be verified by some means. The

OC_CalculateCRC function may be used to generate

a 16-bit CRC that may be used for this purpose.

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Rockwell-automation 1747-PCIS API Software - Open Controller Manual de usuario Pagina 140