Single-ended encoder interface via open collector, Transistor with 24 vdc pull-up (not recommended), Step/direction and cw/ccw (step up/step down) – Rockwell Automation 1398-DDM-xxx USE MNL/ULTRA 200 DIG.SERVO.DR User Manual
Page 88: Interface specifications

Publication 1398-5.0 – October 1998
6-24
Interfaces
Figure 6.29
Single-Ended Encoder Interface via Open Collector
Transistor with 24 VDC Pull-up (not recommended)
twisted pair
twisted pair
Ch A
ENCODER
AX+
AX-
14
J1
Drive
BX+
BX-
16
Drive Chassis
Encoder Case
Ch B
24VDC
24VDC
4
2
Supply
Return
ECOM
IX+
IX-
18
Ch I
24VDC
IN751
5.1 V
IN751
5.1 V
IN751
5.1 V
Table 6.21:
Step/Direction and CW/CCW (Step Up/Step Down)
Interface Specifications
Specification
Description
Minimum
Maximum
Signal frequency
(MHz)
Frequency of the input signal.
1
Pulse Width
(nsec)
Time interval the step (CW/CCW) signal
must remain in a single state for detection.
500
Setup Time
(nsec)
Time interval the direction (CW/CCW) signal
must be stable before the corresponding
step (CCW/CW) signal changes state.
500
The following diagram shows the relationship between STEP and DIRECTION inputs.
STEP
INPUT
DIRECTION
INPUT
Direction data must be
steady for this time period.
500 nsec
minimum
500 nsec
minimum
500 nsec in either
high or low state
500 nsec
minimum
500 nsec
minimum