kernelv_sync_read_write_req()

Prototype

signed long int

kernelv_sync_write_req (unsigned short port,
                                       unsigned long int indexGroup,
                                       unsigned long int indexOffset,
                                       unsigned long int *readLength,
                                        unsigned long int writeLength,
                                       void* data);

Description

Synchronous writing and reading of variables. The variables are identified by Port, indexGroup and indexOffset.

When called, the data pointer contains the data to be written. Specify in writeLength the length of the data area to be written in bytes. Enter the number of bytes to be read in the realLength pointer.

The data read is saved to the memory to which the data pointer points and the number of bytes written is written to *readLength.

At present, the following ports are supported:

Port number	CNC task
551	GEO task
552	SDA task

The meaning of indexGroup and indexOffset depends on the addressed port and can be found in the documentation.

An error code is returned if the function is called while the CNC kernel has not yet started.

Parameter

Name	Type	Meaning
port	unsigned short	Port from which the data is to be read.
indexGroup	unsigned long	Index group of the data item to be read.
indexOffset	unsigned long	Index offset of the data item to be read.
readLength	unsigned long*	Pointer to the return value for the number of bytes returned.
writeLength	unsigned long	Length of the data area to be written.
data	void*	Pointer to memory for the data to be read or written.

Return values

Symbol	Value	Meaning
	0	The function was executed without error.
	-3	The simulation CNC kernel was not yet initialised.
ERR_CNC_RET_MEMORY	-4	The return value(s) does/do not fit into the memory provided.
	6	The transferred port number is not known.
	0x701	The requested service is not supported.
	0x702	Index group is invalid
	0x703	Index offset is invalid
	0x704	The variable addressed must not be written.
	0x705	The data to be written does not match the addressed variable.
	0x706	The job cannot be executed. Possible reasons are: invalid data on write accesses or invalid state of kernelv, e.g. list updating while CNC channel is in error.