Danaher Motion Standalone MMC, Руководство по оборудованию

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28 Standalone MMC Hardware Manual
Installation, Operation, & Maintenance
version 15.1
Danaher Motion
Figure 3-7: Differential Digital Pulse Train
The advantages of using differential signals are:
•
A differential signal is less susceptible to electromagnetic noise. Static or other
interference affects both of the twisted-pair wires equally, so the difference
between the normal and inverted voltage remains unchanged. A differential signal
can be transmitted over a much longer distance or in a much noisier environment
than a single-ended one.
•
MMC hardware circuitry can detect signal loss from an encoder if the signal is dif-
ferential. The application program can be set to shut down the application if such
an error is detected.
3.6 Starting an Application
To start an application:
1. Turn off the main disconnect switch in the control cabinet. If some devices are not
powered from the control cabinet, turn them off also.
2. Connect the connectors according to your diagrams.
3. Turn on power to the system. The MMC goes through the following sequence:
•
The Power light (labeled “P”) goes on and stays on.
•
The Diagnostic light (labeled “D”) goes on briefly, then goes off.
•
If there is an application in the MMC’s memory, the ladder starts scanning and
the Scan light (labeled “S”) goes on. If there is not an application in the MMC’s
memory, use the download command in the PiCPro software to place it there.
3.7 Basic Setup and Maintenance Procedures
Table below summarizes how to proceed when performing certain maintenance and/
or setup functions.
IMPORTANT
Always use differential drivers with differential inputs.
SIGNAL AT A
INVERTED
SIGNAL AT A
DIFFERENTIAL