B&B Electronics I-7060 - Manual - Manual (Page 58)

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I-7000 DIO Manual Rev:B1.2
3.3 Dual Watchdog Operation
Dual Watchdog = Module Watchdog + Host Watchdog
The Module Watchdog is a hardware reset circuit to moni-
tor the module’s operating status. While working in harsh or noisy
environment, the module may be down by the external signal. The
circuit may let the module to work continues and never halt.
The Host Watchdog is a software function to monitor the
host’s operating status. Its purpose is to prevent the network from
communication problem or host halt. When the timeout interval
expired, the module will turn all outputs to predefined Safe Value.
This can prevent the controlled target from unexpected situation.
The I-7000 module with Dual Watchdog may let the con-
trol system more reliable and stable.
3.4 Reset Status
The Reset Status is set while the module power on or reset
by Module Watchdog, and is cleared while the command read Re-
set Status ($AA5) applied. This is useful for user to check the
module’s working status. When the Reset Status is set means the
module is reset and the output may be changed to the PowerOn
Value. When the Reset Status is clear means the module is not
reseted, and the output is not changed.
3.5 Digital Output
The module’s output have 3 different situation :
<1> Safe Value. If the host watchdog timeout status is
set, the output is set to Safe Value.While the module receive the