Counter 1 Up/Down Signal; Frequency Output Signal; Master Timebase Signal - National Instruments NI 6711 User Manual

Counter 1 Up/Down Signal

Frequency Output Signal

Master Timebase Signal

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• Ctr1InternalOutput drives the CTR 1 OUT pin to trigger or control
external devices.
• Ctr1InternalOutput can drive other internal signals.
Refer to Device Routing in MAX in the NI-DAQmx Help or the LabVIEW
Help in version 8.0 for more information.
You can externally input this signal on the P0.7 pin, but it is not available
as an output on the I/O connector. When you enable externally controlled
count direction, Counter 1 counts down when this pin is at a logic low
and counts up when it is at a logic high. If you do not enable externally
controlled count direction, the P0.7 pin is free for general use.
This signal is available only as an output on the FREQ OUT pin. The
frequency generator for your device outputs on the Frequency Output
signal. The frequency generator is a four-bit counter that can divide
its input clock by the numbers one through 16. The input clock of the
frequency generator is software-selectable from the internal 10 MHz and
100 kHz timebases. The output polarity is software-selectable. This output
is set to high-impedance at startup.
The Master Timebase (MasterTimebase) signal, or Onboard Clock, is the
timebase from which all other internally generated clocks and timebases
on the board are derived. It controls the timing for the analog output and
counter subsystems. It is available as on output on the I/O connector, but
you must use one or more counters to do so.
The maximum allowed frequency for the MasterTimebase is 20 MHz,
with a minimum pulse width of 23 ns high or low. There is no minimum
frequency limitation.
The two possible sources for the MasterTimebase signal are the internal
20MHzTimebase signal or an external signal through RTSI 7. Typically the
20MHzTimebase signal is used as the MasterTimebase unless you wish
to synchronize multiple devices, in which case, you should use RTSI 7.
Refer to Chapter 8, Real-Time System Integration Bus
information on which signals are available through RTSI.
5-9
Chapter 5 Counters
(RTSI), for more
Analog Output Series User Manual