Rockwell Automation 1771-QC , D17716.5.25 SER/B SERVO POS - Manual (Page 69)

Installing the Assembly
Chapter 6
6Ć19
1. Connect a third pole of the selector switch to the jog forward
(hardware start) terminal of the 1771-ES expander.
2. Connect a momentary-contact jog forward switch to the selector
switch contact corresponding to manual on the third pole.
3. Connect an output terminal of a Contact Output Module (cat. no.
1771-OZ) to the selector switch contact corresponding to auto on the
third pole.
In the manual mode, the jog forward switch controls whether the input is
high or low. In the auto mode, the hardware start output from the
1771-OZ module controls whether the input is high or low.
You can use the ladder diagram program to generate a hardware start
signal (by closing the contacts of 1771-OZ module output) when each of
several axes generates a hardware done signal. You can connect the same
hardware start signal to several 1771-ES expanders to coordinate the start
of motion following halt moves for these axes.
Connecting a Differential Encoder
Figure 6.10 shows details of how to connect a differential encoder. With a
differential encoder, reversing the connections on a channel or changing
the position of the polarity jumper for the channel reverses the polarity of
the signal on that channel. Set the polarity so that the marker is true at the
same time that channels A and B are true.
If you switch channel A with channel B, you reverse the direction of the
feedback. If the direction of the feedback does not correspond to the axis
motion direction, as you have defined it, switch channel A with channel
B.
Ground the shield at the I/O chassis end.