Nexcom SBC watchdog timer

[Neil.Pate]

Hi All,

Has anybody had any success in communicating with the watchdog timer (WDT) built into industrial single board computers?

I am using a Nexcom Peak 777 which seems to have a fairly standard WDT. Apparently it just needs a configuration written to a control register on 0xF2, so I have done this using the Port Out VI (WinXP), but it does not seem to be doing anything. I would expect if I had the config set up correctly after the specified timeout period the PC would reset and it does not.

There is no control at all of the WDT in the BIOS.

Any ideas?

Thanks

[rsw]

Hi,

Looking at page 33 of the manual for the 777 it appears you have to first set this register before applying:

1. MOV al, 0h //set to 0
2. AND al, 10000000b //Set timeout value (1-255)
3. OR al, 10000000b //activate this setting
4. MOV dx, F2h //set the above to the register

Are you doing these to setup the board?

Kind Regards,

[rsw]

Link doesn't appear to work, if you search "Nexcom SBC manual 777" it's the 6th result, interestingly this forum is the first result!

Kind Regards,

[Neil.Pate]

Hi Rob,

It turns out the manual for the SBC is completely wrong. I ended up using the programming guide for one of the HMI PCs sold by NI, it contains the same IO chip (the W83627HF).