Chapter 3
Connecting the UMI-7774/7772 to Drives and Other Devices
©
National Instruments Corporation
3-21
National Instruments UMI-7774/7772 User Manual
Figure 3-16.
UMI-7774/7772 Optically Isolated Sinking Input Interface Circuit
and Connection to Sourcing Output Sensor
Caution
Failure to follow these guidelines may result in motion that stops at a limit,
but then travels through it, potentially damaging the motion system. Incorrectly wired
limits may prevent motion from occurring at all.
For the end of travel limits to function correctly, the forward limit must be
located at the forward or positive end of travel, and the reverse limit must
be located at the negative end of travel.
Limit and Home Status Indicators
The UMI-7774/7772 has yellow status LEDs for the forward limit, reverse
limit, and home input signals. Refer to Figure 3-5 for the location of these
LEDs. You can configure the limit and home status LEDs as active-low or
active-high using the switch for the axis labeled
LIMIT LED
. The down
position of the switch corresponds to active-low and the up position of the
switch corresponds to active-high.
Note
Configuring the limit and home status LEDs on the UMI-7774/7772 does not
configure the limit and home inputs themselves as active-high or active-low. You must
configure the limit and home inputs separately on the National Instruments motion
controller using MAX or NI-Motion driver software.
The yellow status LEDs for the limits and home inputs illuminate when the
inputs are active.
Input
Vcc
UMI-7774/7772
Current Limiter
PNP
(Sourcing)
Output Device
Viso
Ciso
V–
V+
Out
Out
