Chapter 5
Signal Connections
©
National Instruments Corporation
5-13
Wiring Concerns
For proper use of each ADC input channel, the analog signal to be
measured should be connected to the channel input and its ground reference
connected to the Analog Input Ground.
Note
If an external reference voltage is used, it must not be connected to the analog
reference output, since this is an output signal only. You should, however, connect the
external reference’s common to the Analog Input Ground pin for proper A/D reference and
improved voltage measurement.
Other Motion I/O Connections
The 7344 controller provides other motion I/O connections as follows:
•
Host +5 V—This is the host computer’s in5 V supply. It is used
to detect when the host computer is powered and as an interlock to shut
down external motion system components when the host computer is
turned off.
Caution
The host +5 V signal is limited to <100 mA and should not be used to power any
external devices, except those intended in the host bus monitor circuits on the UMI and
drive products.
•
Shutdown—The shutdown input signal, when enabled in software, can
be used to kill all motion by zeroing the analog outputs and freezing
the stepper pulse and/or direction outputs.
Digital I/O Connector
All of the 7344 controller’s general-purpose digital I/O lines are available
on a separate 68-pin digital I/O connector. The pin assignments for this
connector are shown in Figure 5-7.
