Rockwell Automation 1771-QB Linear Pos. - Manual (Page 38)

Hardware Description
Chapter 4
4Ć9
Important: If you want to connect a discrete output of one axis to the discrete
input of another axis, the minimum discrete output supply voltage is 11.6 VDC.
This accounts for the voltage drop of 1.6 VDC shown above and provides the
minimum voltage required to drive a module discrete input (10 VDC).
ATTENTION: The discrete outputs can withstand a short circuit for
a few seconds. However, a continuous short circuit will damage the
module’s discrete output transistor.
OUTPUT 1
When OUTPUT 1 (terminals 36/37) is configured as an in-position output, it
turns off when axis movement toward a commanded endpoint begins and turns
on when the axis enters the in-position band (defined in the parameter block).
You can connect an in-position output to a hardware start input to provide a
simple form of axis coordination.
When this output is configured as a programmable output, its state is
determined by the configuration information provided in the motion blocks.
(See Chapter 9.)
OUTPUT 2
When OUTPUT 2 (terminal 38/39) is configured as a loop fault output, it is
high under normal axis operation. When the module detects a fault in the axis,
the loop fault output goes low.
You can connect the loop fault output to the hardware stop input of other control
loops so all axis movement will stop if a fault occurs. The loop fault output then
provides the low signal required by the hardware stop input of the other axis.
As with OUTPUT 1, OUTPUT 2 can be configured as a programmable output
and its state determined by information in the motion blocks.
You must provide external DC power for the input and output circuits. You
could use a single supply, but you’ll maintain maximum separation and keep
noise to a minimum by using four separate power supplies. In less critical
applications, you could power two or three circuits from the same supply.
Power Supplies