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MVS-8100D Hardware Description
Cognex MVS-8100D and CDC Cameras Hardware Manual
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External I/O Module Adds Conversion Delay
The external I/O module converts all digital TTL signals from the MVS-8100D into
opto-isolated signal pairs. The opto-isolation circuitry of the external I/O module adds a
delay of 100 to 300 microseconds, compared to a pure TTL signal. For comparison, the
response time of a typical TTL signal is about 1 microsecond.
The same output device, connected to both the external I/O module directly to the
MVS-8100D’s I/O port with cable 300-0358 will receive its signal 100 to 300
microseconds slower on the external I/O module compared to the 300-0358 cable.
A delay of this small magnitude is not visible to the naked eye, but may have a
cumulative effect when multiplied over many rapid image acquisitions. Take this delay
into account when calculating your maximum image processing throughput if you plan
to use the external I/O module.
External I/O Module Circuit Logic
Figure 19 shows a typical input schematic to help you determine how to wire your input
devices to the external I/O module.
Figure 19. Typical input schematic for external I/O module
Opto-isolator
To
+5 V
+5 V
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