Drivers Stop when mailer sends email

[jbesselm]

We have recently deployed a proven mailer process to a customers existing installation. The process sends out a text message based on alarm conditions. On our customers computer whenever the mailer object is triggered, both an AB driver (ethernet to a SLC500) and a Modbus driver (TCP/IP) generate communication alarms and will not restart until Lookout is shutdown and restarted.  Simply restarting the driver process will not restart the communications. The Modbus error is "No response from socket", the AB  error is "cannot communicate with device (code=2)". There is also a DirectLogic Plus driver object that provides ethernet communications to several Koyo PLCs, this driver is not affected. I can NOT duplicate this at our office, our test setup works as expected. We have tried this both with and without using a SMTP server, there is no difference. We have also used this same basic arrangement at other sites without any problems.

The system is Lookout 6.1 with updates, the PLC network(ethernet) has 1 SLC500, 4 direct Logic DL260 and DL06s, one Modbus device through a Digi Serial server, 2 Cmore touch screens, and 1 panelview touch screen. The troubled computer is WindowsXP SP3, has two nics, one wired for PLCs and one wireless for internet. Our test computer that works just fine is also WindowsXP SP3, has 2 wired nics one for PLC and one for internet. The nics are on different subnets.

All ideas as to what might be happening are appreciated.

Jim Besselman

[Ryan.S]

First, we need to check if the driver is still trying to connect the device. Go to edit mode, select Options->AB Ethernet Option, or Modbus Ethernet Optioin, enable it, input file path, such as d:\. Then, after the communication fails, check the log file. The AB or Modbus driver should retry after the failure. The log file maybe tells us the error it gets from the socket.

Then, you can try to ping the PLC after the communication fails. Maybe the driver sends data to the wireless connection.

[jbesselm]

Hi Ryan;

Thanks for the suggestions. Attached are two log files. I've deleted most of the polls & replys prior to triggering the mailer. After the coms stopped I was able to ping each PLC. I will try to get some logs for comparison from a system in my office that works as expected but it will be couple of days.

Thanks

Jim Besselman

[Ryan.S]

Was the email successfully sent by Lookout?

Are you able to ping both plc and the smtp server at the same time?

At the beginning, I thought it was a network problem. Maybe only one network card was active at the same time. But if you are able to ping both plc and internet address, the problem maybe in lookout. When the communication is good, don't trigger the email, but view some web pages on internet through the wireless connection, will the driver also stop?

I'm not so familiar with the network. Does anyone else know if this is a network configuration problem? I suspect the two network cards can be the issue, but myself don't know much.

[jbesselm]

The email is successfully sent by Lookout. I haven't tried pinging the smtp server but while the communication is good but since the email is sent I expect that we can. We can view web pages normally and send and receive email using outlook express without causing any disruption to the PLC communications. The problem is somewhat unique to either this particular computer or the network settings. We have been using the mailer object for several years with lookout versions 5.1 and higher and various PLC drivers with out seeing this before. I have seen another instance where an onboard network adapter caused Lookout problems even though Lookout was not using the network. In that case the issue was solved by installing a new network card and disabling the onboard network adapter. I'm pretty sure replacing the computer will fix this but I'd really like to know what the cause is.  I guess my next step would be to use a utility to monitor the network traffic unless you've got some other ideas.

Thanks

Jim Besselman