Comm Error unlocking PLC

[mhw]

I was trying to connect to an old D0-05 PLC using DS6 with a serial connection. Configuring the K Sequence link gives a green light. Trying to connect to the PLC then gives the error message, "Comm Error unlocking PLC". I tried both ports 1 and 2 with the same result. I verified that I can connect to a different 05 that I found at my office. Unfortunately I was unable to find an ECOM card to try on the unresponsive PLC. The program in the PLC is still working and rebooting the PLC or changing the mode switch did not help.
Any ideas what I can try?

[franji1]

You might try looking at the Link Info page for that Comm Link to get some idea of the specific issues/errors being reported.  There should have been more detail in the message box as to why it could not unlock the PLC.

From DSLaunch's Link's group, you should be able to click (right-click?) to get a menu or button to get Link Info with error details.

Let us know what you see.

[rlp122]

Try DirectNET.  On some older DL05's the comm port can become unresponsive to K-sequence.  If you can get it to connect, update the firmware asap.

[mhw]

Thanks for your responses.
I finally was able to get back to that site. This time it connected without any problems. Not sure what the issue was.