Rockwell Automation 1746-HSTP1 Stepper Controller Module/ User Manual - Manual (Page 52)

Publication 999-121 - December 1999
Configuration and Programming 5-17
Using the N Files for Motion Commands
The following example is used to denote an axis move equal to 1001
pulse counts, in the CW (
+) direction. Word N9:23 contains the
information in the (LSW) words which is the fine position in counts.
These values can range from 0 to 999. Coarse position information is
stored in word N9:22. The combination of coarse and fine position
information determines how many counts the axis moves. If there is
no coarse position information, a negative sign in the fine position
word can be used to denote the axis direction. The move segment is
made up of N9:22 and N9:23. N9:22
= 1 counts and N9:23 = 1 count.
Motion commands are executed using the copy instruction as
indicated in the program example represented by rung 3 of the
“Application Examples” in Chapter 6 of this manual.
Quadrature Encoder Input
The Module supports a quadrature encoder with differential line
driver outputs. The marker channel of the encoder is optional and
provides an additional level of accuracy to the original home position
(reference position), if required. The same circuitry is used for the
loop back diagnostics and the quadrature encoder. The quadrature
encoder output is read directly as counts and passed through to the
backplane as the feedback value in words 4 and 5.
Use of Direct Inputs
There are a total of six direct inputs to the Module. They are: External
Interrupt Input, Home Limit Switch Input, Home Proximity Switch
Input, CW Limit Switch Input, CCW Limit Switch Input, and Pulse
Train Enable/Disable Input. They connect to Module Input/Output
Function Command (Reserved)
Pos
(MSW)
Pos
(LSW)
Vel
(MSW)
Vel
(LSW)
Accel Decel
Address 0 1 2 3 4 5 6 7
N9:20 1 0 1 1 10 0 6 6
IMPORTANT
If the encoder is used, it must be disconnected from
the controller whenever loop back diagnostics are
being performed.