Hardware Watchdog Timeout Issues

[Bolt]

BX-DM1E-18ED23 OS 2.10.3
I'm doing some program tweaking on my test bench (LAN writes), and while doing a Runtime Edit, I routinely get the following (but not on every write):

Code: [Select]

Error! Newly downloaded project is invalid. The OLD project int he PLC remains the currently running project. Check the System Event Log in the System Information dialog for details.
The Event Log shows that the PLC rebooted following hardware watchdog timeout.
The System Status doesn't show any Error Messages and not much for descriptive Last Errors, only Divide by zero (an unconfigured analog scaling math instruction).

Could it be scan time related? ScanTime is around 10-11 ms (I know, not great...) and MaxScanTime approaches 18ms sometimes, but it's hard to get a handle on during watchdogs, as it doesn't update during the watchdog reboot. When it's back, its back around 10ms and 14ms max.

Doing a new Program Mode Download to PLC writes it near instantly (presumably because the new code is already on the PLC).

I'm not seeing any issues such as pointers out of range (I think it would give me an Error Message accordingly?), etc. I haven't encountered this before in run time edits, local network or remote via VPN. I'd rather not field deploy code with a watchdog issue and potential run time edit failures, so trying to get to the bottom of it on the bench.

[BobO]

Scan time shouldn't cause a hardware watchdog, but it could cause comm issues, depending on your comm settings.

If the write is completing instantly something is going wrong, likely related to comm failures. Are you getting retries and errors?

[Bolt]

The whole process takes about 30 seconds from clicking OK on the runtime edit. At about 20 seconds the HMI shows a "PLC not responding" message, and a second or 2 later, DmD's Link Info turns red in the toolbar. It shows Transport protocol error at 21 and 26 seconds, followed by two Comm session failed notices at 26 seconds.

Then when I click Program mode write, it takes less than 2 seconds to roll out the new code.

[BobO]

The whole process takes about 30 seconds from clicking OK on the runtime edit. At about 20 seconds the HMI shows a "PLC not responding" message, and a second or 2 later, DmD's Link Info turns red in the toolbar. It shows Transport protocol error at 21 and 26 seconds, followed by two Comm session failed notices at 26 seconds.

Then when I click Program mode write, it takes less than 2 seconds to roll out the new code.

That sounds like it's rebooting when you write the program. Sounds like it is repeatable? I'd like to try to dupe it if so.

[Bolt]

Emailed the project to support.

[plcnut]

I have this same problem.
It started happening as soon as I referenced the SD card in my project.

[BobO]

I have this same problem.
It started happening as soon as I referenced the SD card in my project.

Bolt's problem was related to the EIP Scanner and run mode updates. It's fixed and will be out shortly. If you have something repeatable (unrelated to EIP Scanner), I'm happy to look at it.

[plcnut]

I have this same problem.
It started happening as soon as I referenced the SD card in my project.

Bolt's problem was related to the EIP Scanner and run mode updates. It's fixed and will be out shortly. If you have something repeatable (unrelated to EIP Scanner), I'm happy to look at it.

I am using EIP Scanner as well, but did not notice this until I started using the SD card.
It is very repeatable. I'll see if I can get you a sample project.

[plcnut]

I have this same problem.
It started happening as soon as I referenced the SD card in my project.

Bolt's problem was related to the EIP Scanner and run mode updates. It's fixed and will be out shortly. If you have something repeatable (unrelated to EIP Scanner), I'm happy to look at it.

I deleted everything from my project except the SD card code and the EIP scanner configurations and would get a watchdog on every runtime edit.
I then deleted the EIP configs (But left the SD card code) and the problem is gone.
It would appear that this is, in fact, related to the EIP scanner.

[BobO]

I deleted everything from my project except the SD card code and the EIP scanner configurations and would get a watchdog on every runtime edit.
I then deleted the EIP configs (But left the SD card code) and the problem is gone.
It would appear that this is, in fact, related to the EIP scanner.

That does sound like the same problem. The window appears to be small enough to go unnoticed until the scan time gets high. I think it might also depend on the adapter not being very stable, in Bolt's case the adapter was disconnected. I can send you the new bits if you'd like to try them.

[plcnut]

I deleted everything from my project except the SD card code and the EIP scanner configurations and would get a watchdog on every runtime edit.
I then deleted the EIP configs (But left the SD card code) and the problem is gone.
It would appear that this is, in fact, related to the EIP scanner.

That does sound like the same problem. The window appears to be small enough to go unnoticed until the scan time gets high. I think it might also depend on the adapter not being very stable, in Bolt's case the adapter was disconnected. I can send you the new bits if you'd like to try them.

Scan time is 4.6ms
I have 6 EIP adapters. Only one of them is physically connected right now, because this project is still in development.

I would be happy to test the bits.

[BobO]

Sent.

[plcnut]

The new bits work beautifully.
Thanks!