Function
When the user buffer mode is used to transfer data, retrieves data size that is necessary for one sampling.
This data size is decided by the used number of channels and the attached data settings on the device that uses bus-master transfer.
Therefore, you need set the number of channels (AioSetAiChannels) and set attached data before retrieve the data size by this function.
Format
Ret = AioGetAiSamplingDataSize ( Id , DataSize )
Parameters
Id [ C, C++ : short ] [ Python : ctypes.c_short ]
Specifies the Device ID retrieved from AioInit function.
DataSize [ C, C++ : short * ] [ Python : ctypes.POINTER(ctypes.c_short) ]
Specifies the address of the variable that stores the data size.
Data size is stored as the number of packets. 1 packet = 4 bytes.
Return value
Ret [ C, C++ : long ] [ Python : ctypes.c_long ]
|
Return values |
Content |
|
0 |
Normality completion |
|
7 |
Execute AioResetDevice function because the device has recovered from standby mode |
|
10001 |
Invalid Id was specified |
|
10002 |
AIO driver can't be called |
|
12020 |
Pointer to DataSize is NULL |
|
20001 |
This function can't be used by this device |
|
20002 |
Can not use while by another device works |
|
20003 |
Can not use because another process is using the device |
Initial value
In all devices, DataSize = 1
Remarks
This function cannot be used on devices without the analog input function.
If the device is in operation, the function cannot be performed.
Example
Retrieves data size that is necessary for one sampling.
|
C, C++ |
long Ret; |
|
Python |
Ret = ctypes.c_long() |