Programmable Power-Up State Function; Watchdog Timer Function; Reset Protection - Advantech MIC-3758DIO User Manual

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1.2.3 Programmable Power-Up State Function

User-configurable power-up states are useful for ensuring that MIC-

3758DIO powers up in a known state. Power-up states are programmed in

the EEPROM through the driver.

The watchdog timer is a software configurable feature used to set critical

outputs to safe states in the event of a software failure. If there is loss of

communication between the application and MIC-3758DIO, if the watch-

dog timer is enabled and MIC-3758DIO does not receive a watchdog

clear software command within the interval time specified for the watch-

dog timer, the outputs go to a user-defined safe state and remain in that

state until the watchdog timer is disabled and new values are written by

the software. After the watchdog timer expires, MIC-3758DIO ignores

any writes until the watchdog timer is disabled. You can set the watchdog

timer timeout period through the WDT register to specify the amount of

time that must elapse before the watchdog timer expires. The counter on

the watchdog timer is configurable up to 2

-1 x 100 ns (approximately

seven minutes) before it expires.

If the system has undergone a hot reset (i.e. system power was not turned

off), MIC-3758DIO can either retain output values of each channel, or

return to its default configuration as power up status, depending on its on-

board jumper setting. This function protects the system from wrong oper-

ations during unexpected system resets.

MIC-3758DIO User Manual

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