B&B Electronics I-7060 - Quick Start Guide - Manual (Page 44)

Getting Started for I-7000 Series Modules
Date: Jan-08, 2002 Version 1.02 page: 44
5.4 Comparison of Host Watchdog and Module Watchdog
Host Watchdog Module Watchdog
Software or
Hardware Software Watchdog
Built-in firmware Hardware Watchdog
Circuits in module
Purpose To monitor the Host PC
For use in all output modules To monitor the Module
For use in all modules
When activation
occurs Host is down
Communication line
is broken
Module fails
Excessive work environment
noise
What to do Module goes to safe state
Module status S = 0x04
Module’s output goes to
safe values
All output commands
will be ignored.
Module resets
Module Reset status S = 1
Module’s output goes to
PowerOn values
CLEAR module-
status ~AA1
S is set to 0
READ module-
status ~AA0
S = 4
" Host is down
S = 0 " Host is OK
READ and RESET
module-reset –
status $AA5
S = 1
" Module Reset
S = 0 " Not reset
Setup steps Setup safe values
Setup the timer interval value
of Host Watchdog and enable
the Host Watchdog
Setup Power-On values
Send “Host is OK” ~**
Send the "~**" command to
modules before timeout of Host
Watchdog’s timer.