Table of Contents
Advertisement
Chapter 7
Counters
Synchronization Modes
Duplicate Count
Prevention Enabled
Yes
No
No
No
No
M Series User Manual
Enabling Duplicate Count Prevention in NI-DAQmx
You can enable duplicate count prevention in NI-DAQmx by setting the
Enable Duplicate Count Prevention attribute/property. For specific
information about finding the Enable Duplicate Count Prevention
attribute/property, refer to the help file for the API you are using.
The 32-bit counter counts up or down synchronously with the Source
signal. The Gate signal and other counter inputs are asynchronous to the
Source signal. So M Series devices synchronize these signals before
presenting them to the internal counter.
M Series devices use one of three synchronization methods:
•
80 MHz source mode
•
Other internal source mode
•
External source mode
In DAQmx, the device uses 80 MHz source mode if you perform the
following:
•
Perform a position measurement
•
Select duplicate count prevention
Otherwise, the mode depends on the signal that drives Counter n Source.
Table 7-6 describes the conditions for each mode.
Table 7-6. Synchronization Mode Conditions
Type of
Measurement
Any
Position Measurement
Any
All Except Position
Measurement
All Except Position
Measurement
Signal Driving
Counter n Source
Any
Any
80 MHz Timebase
20 MHz Timebase,
100 kHz Timebase,
or PXI_CLK10
Any Other Signal
(such as PFI or RTSI)
7-38
Synchronization
Mode
80 MHz Source
80 MHz Source
80 MHz Source
Other Internal Source
External Source
ni.com
Hide quick links:
Advertisement
Table of Contents
