Ethernet Module Interface (EMI)
– API Description
Copyright IXXAT Automation GmbH
80
IEM Manual, 1.5
Parameter
Dir.
Description
td_brdRef
IN
unique IEM reference
w_length
IN
data length to be copied by serial interface
Return Value
Description
COM_k_OK
shared memory released.
COM_k_INVALID_BOARD
invalid IEM reference
COM_k_BUSY
no access to shared memory possible. Retry limit was hit.
COM_k_INVALID_STATE
routine called in invalid state
COM_k_ERROR
parameter error
4.1.2.45 EMI_ioAcyclDataRead()
COM_e_ERROR EMI_ioAcyclDataRead(COM_t_BOARD_REF td_brdRef,
PVOID pv_dest,
UINT16 w_offset,
UINT16 w_length);
Description
This function copies data from the shared memory area of acyclic data to the
specified address. The access to data is protected by means of a hardware
semaphore. The semaphore is implemented on the IEM. If "1" is written to the
semaphore register and a subsequent read also returns "1" then the access
was successful. Otherwise the semaphore is busy. The write access to the
semaphore is repeated several times. If the maximum number of retries is ex-
ceeded the function returns COM_k_BUSY. This limitation avoids a deadlock
in case of a system crash on the IEM. The application has to convert the pro-
tocol specific format of complex data structures to the local format.
Remarks
-
Parameter
Dir.
Description
td_brdRef
IN
unique IEM reference
pv_dest
IN
destination address
w_offset
IN
offset to the data in shared memory
w_length
IN
length of data
Return Value
Description
COM_k_OK
data copy OK.
COM_k_BUSY
no access to shared memory possible. Retry limit was hit.
COM_k_INVALID_BOARD
invalid IEM reference