National Instruments NI PCI-6110 - Manual (Page 27)

Chapter 3 Hardware Overview
NI PCI-6110/6111 User Manual 3-8 ni.com
The analog trigger circuit generates an internal digital trigger based on the
AI signal and user-defined trigger levels. This digital trigger can be used by
any DAQ-STC timing section, including the AI, AO, and general-purpose
counter/timer sections. For example, the AI section can be configured to
acquire n scans after the AI signal crosses a specific threshold. As another
example, the AO section can be configured to update its outputs whenever
the AI signal crosses a specific threshold.
Digital I/O
The NI PCI-6110/6111 contains eight lines of DIO for general-purpose use.
You can individually software-configure each line for either input or
output. At system startup and reset, the DIO ports are all high-impedance.
The hardware up/down control for general-purpose counters 0 and 1 are
connected onboard to DIO6 and DIO7, respectively. Thus, you can use
DIO6 and DIO7 to control those counters. The up/down control signals,
GPCTR0_UP_DOWN and GPCTR1_UP_DOWN, are input only and do
not affect the operation of the DIO lines.
Timing Signal Routing
The DAQ-STC provides a flexible interface for connecting timing signals
to other devices or external circuitry. The NI PCI-6110/6111 uses the
RTSI bus to connect timing signals between devices and the Programmable
Function Input (PFI) pins on the I/O connector to external circuitry. These
connections enable the NI PCI-6110/6111 to both control and be controlled
by other devices and circuits.
You can control 13 timing signals internal to the DAQ-STC with an external
source. These timing signals can also be controlled by signals generated
internally to the DAQ-STC, and these selections are fully software
configurable. For example, the signal routing multiplexer for controlling
the STARTSCAN signal is shown in Figure 3-10.