User`s manual

NA-821 Series Network Appliance User’s Manual
Enabling LAN Bypass Feature
59
Appendix A
Enabling LAN Bypass Feature
What is the LAN by-pass meant for NA-821 Series? It doesn’t have any
down time in network connections for two other network segments
(LAN1 and LAN2) when any fetal errors occur to this device.
The LAN by-pass feature covers three levels as below:
1. Power loss
While the AC power loss occurs to this device, the LAN1 and
LAN2 still can communicate with each other through hardware
relay like as a short cut between two segments. If the power
inlet can be normally done, the relay will turn to another
correct position.
2. GPIO control
It acts like a switch of the application software. You can
enable the hardware relay feature through the GPIO control
through the application programs. Then, the software solution
provider can be more flexible to make it close with the
program.
3. WDT (Watchdog Timer)
The hardware supports the WDT (Watchdog Timer) function.
While time-out happens after a defaulted period, the WDT will
reset the system or make a short cut for two specific
segments by hardware relay.
The sample codes for the above features can be found in
the CD, and they are only for customers’ reference as
remarked.