©
National Instruments Corporation
17
NI UMI-7774/72 User Guide and Specifications
Analog Output
The UMI-7774/72 analog output signals are used as command outputs to servo drives or as
general-purpose voltage outputs. To help keep digital noise separate from the analog outputs, Pin 9
provides a separate analog output ground connection. Use this analog ground connection instead of
a digital ground when you connect the UMI-7774/72 to servo drives. Analog outputs are pass-through
signals from the motion controller. A pass-through signal provides passive filtering on the signals, which
does not affect the voltage range or current-handling capability of the signals.
Step (CW) and Dir (CCW)
The UMI-7774/72 Step (CW) and Dir (CCW) signals are used as command outputs to a stepper drive.
Some stepper drives require clockwise direction (CW) and counterclockwise direction (CCW)
commands rather than Step and Dir commands. You can configure National Instruments motion
controllers to provide either type of stepper commands. Both Step (CW) and Dir (CCW) signals are
pass-through signals.
Voltage Considerations for the UMI-7774/72
To cause current to flow through the input, the voltage applied to the following types of inputs must be
greater than 3.5 V and less than 30 V.
•
Fault inputs
•
Limit and home inputs
•
Global Stop inputs
•
Trigger inputs
•
General-purpose digital inputs
Also, the source must be able to provide at least 7.2 mA to turn on the optical isolator and result in an
ON condition. When the applied voltage is below 2 V, the input results in an OFF condition.
5
NC
No
6
Enable
Yes
7
Fault +
Yes
8
V
iso
(Output)
Yes
9
Analog Output Ground
No
10
Digital Ground
No
11
Digital Ground
No
12
Dir (CCW)
No
13
NC
No
14
Fault –
Yes
15
C
iso
Yes
†
Provides 1 A maximum output current, shared between Control connector pin 3, Feedback connector
pins 4 and 8, and Trigger/Breakpoint connector pin 3.
Table 2.
Per Axis Control Connector Pin Assignment (Continued)
Pin
Signal
Optically Isolated
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com
