Watch Dog Timer - Galil Motion Control DMC-18 2 Series User Manual

The standard voltage level is TTL (zero to five volts), however, voltage levels up to 12 Volts are
acceptable. (If using differential signals, 12 Volts can be input directly to the DMC-18x2. Single-
ended 12 Volt signals require a 5-7V bias voltage input to the complementary inputs.)
The DMC-18x2 can accept analog feedback instead of an encoder for any axis. For more information
see description of analog feedback in Chapter 2 under the section titled "Test the encoder operation".
To interface with other types of position sensors such as resolvers or absolute encoders, Galil can
customize the controller and command set. Please contact Galil to talk to one of our applications
engineers about your particular system requirements.

Watch Dog Timer

The DMC-18x2 provides an internal watch dog timer which checks for proper microprocessor
operation. The timer toggles the Amplifier Enable Output (AEN), which can be used to switch the
amplifiers off in the event of a serious DMC-18x2 failure. The AEN output is normally high. During
power-up and if the microprocessor ceases to function properly, the AEN output will go low. The
error light will also turn on at this stage. A reset is required to restore the DMC-18x2 to normal
operation. Consult the factory for a Return Materials Authorization (RMA) Number if your DMC-
18x2 is damaged.
DMC-18x2
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com
Chapter 1 Overview • 5