Figure 4-12. Gpctr1_Out Signal Timing; Gpctr1_Up_Down Signal - National Instruments DAQ PCI-4451 User Manual

Chapter 4 Signal Connections
GPCTR1_SOURCE
GPCTR1_OUT
(Pulse on TC)
GPCTR1_OUT
(Toggle output on TC)
PCI-4451/4452 User Manual
As an output, the GPCTR1_GATE signal monitors the actual gate signal
connected to general-purpose counter 1. This is true even if the gate is
externally generated by another PFI signal. This output is set to tri-state at
startup.
GPCTR1_OUT Signal
This signal is available only as an output on the GPCTR1_OUT pin. The
GPCTR1_OUT signal monitors the TC device general-purpose counter 1.
You have two software-selectable output options—pulse on TC and toggle
output polarity on TC. The output polarity is software selectable for both
options. This output is set to tri-state at startup. Figure 4-12 shows the
timing requirements for the GPCTR1_OUT signal.

Figure 4-12. GPCTR1_OUT Signal Timing

GPCTR1_UP_DOWN Signal

This signal can be externally input on the DIO7 pin and is not available as
an output on the I/O connector. General-purpose counter 1 counts down
when this pin is at a logic low and counts up at a logic high. This input can
be disabled so that software can control the up-down functionality and
leave the DIO7 pin free for general use. Figure 4-13 shows the timing
requirements for the GATE and SOURCE input signals and the timing
specifications for the OUT output signals of your PCI-4451/4452 device.
TC
4-22 © National Instruments Corporation