Appendix A
-
Operation Details
176
MMC Hardware Manual
G & L Motion Control Inc.
Figure A-3: Signals Transmitted by a Quadrature Encoder with Differential
Outputs
The maximum input frequency is 250,000 lines per second, which results in
1,000,000 Feedback Units (FUs) per second.
Figure A-4: Counting Quadrature Pulses
There is a 24-bit up/down counter for each channel. It is incremented or
decremented on each A, B edge. There is also a 24-bit latch associated with each
encoder channel.
The module can be programmed so that the counter value is “latched” or stored
under one of these conditions:
•
an index pulse from the encoder
•
a positive or negative transition of the fast input
•
the next index pulse after the required transition of the fast input
Each of the five 24-bit latches has a
fast 24 VDC input
associated with it. Each
input is optically isolated. This input is intended to receive a signal from a device
other than an encoder. It is typically used for referencing or synchronization
purposes.
Fast input characteristics include:
•
the detection of a signal occurs faster than it does for the DC inputs in other
modules, due to less filtering. Because of this there is also less noise
immunity.
ROTATION SPEED
0
A
A
B
B
OUTPUT
B
A
1
2
3
4
5
6
7
8
9
10
11
12
Encoder Count
The module counts positive
transitions at both channel A
and channel B. One quadrature
cycle in this case gives
4 feedback units.
Summary of Contents for MMC-A2
Page 1: ...Standalone MMC TM Hardware Manual Version 15 0 G L Motion Control Inc...
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Page 36: ...Installation Operation Maintenance 28 MMC Hardware Manual G L Motion Control Inc...
Page 124: ...Standalone Digital MMC Control 116 MMC Hardware Manual G L Motion Control Inc...
Page 136: ...MMC Ethernet TCP IP Option Module 128 MMC Hardware Manual G L Motion Control Inc...
Page 175: ...CE and EMC Guidelines G L Motion Control Inc MMC Hardware Manual 167...
Page 176: ...CE and EMC Guidelines 168 MMC Hardware Manual G L Motion Control Inc...
Page 177: ...CE and EMC Guidelines G L Motion Control Inc MMC Hardware Manual 169...
Page 178: ...CE and EMC Guidelines 170 MMC Hardware Manual G L Motion Control Inc...
Page 186: ...Appendix A Operation Details 178 MMC Hardware Manual G L Motion Control Inc...