Measurement Computing ADLIB WIN - Manual (Page 79)

Chapter 21 Clocking Modes 20-3
20.3 AL_GetActualClkRate
Prototype C\C++
(32 bit) ERRNUM AL_GetActualClkRate(LHLD lhld, double *dActualRate);
Visual Basic for Windows
Function AL_GetActualClkRate(ByVal lhld As Long, ByVal dActaulRate As Double)
As Long
LHLD lhld handle of the LDSD
double dActualRate
points to a double value to receiving the value.
The AL_GetActualClkRate function is used to determine the frequency actually available by a device's
clocking hardware. The clock frequency specified in the AL_SetClockRate.vi function may not be
achievable due to hardware limitations.
Note: The AL_SetClockRate clocking rate parameters are not programmed to a device until it initialized
with AL_InitializeDevice. This function uses the clocking rate parameters from the last call to the
AL_SetClockRate function to determine the actual available hardware rate and does not reflect the current
devices programmed rate until the device has been initialized. Once a device has been initialized, if the
AL_SetClockRate is called again with different clocking rate parameters this function will not return the
current device's programmed clocking frequency until the device is re-initialized. Therefore this function
only returns the actual rate that can be set by the AL_SetClockRate function. To get the current Clocking
Rate programmed to the device, it must be initialized before calling this function.
Parameter Description
lhld Identifies the instance of the logical device subsystem.
dActualRate
Contains the actual hardware clocking rate.
Returns:
On success ERRNUM is set to 1, otherwise ERRNUM contains the last error code that occurred during the
call.
Related Functions:
AL_SetClockSource
AL_SetClockRate
AL_MaxClkRate
AL_GetClockStruct
Supported Logical Device Subsystems:
Pci55xx Series: ADC0, DAC0, DAC1