Had occasion to pick up a nice trick for Linx. After a sudden disappearance of a certain PLC which had been showing in RS Who a customer support engineer suggested I remove two files in the C:\Program Files\Rockwell Software\RSCOMMON directory. They are both named Harmony, one extension .hrc and the other .rsh . Deleted them and next launch they are regenerated. Disappearing PLC returned to site.. Ain't software fun?

I just had to do this while working on a DeviceNet system using RSNetworx. While setting the nodes the software stopped recognizing the latest device i connected to the system. I eventually called tech support and they had me do the same thing. Apparently these files can get corrupted pretty easily and then will fail to shut down when RSLinx is shutdown.

A quick search yielded that deleting "Harmony" can fix a myriad of other weird RSLinx issues. The name rings a bell from using RSLinx in the past, but I can't place a finger on it. I'd really like to know what it is and does.

Isn't the Harmony file the program that actually loads your drivers into the system drivers? I know when watching Rs_linx's boot up you see it is the first file that is ran.

Got curious so I posted the question on PLCs - the answer included an AB knowledgebase post. Seems to me that it's more of a legacy wrapper.

http://www.plctalk.net/qanda/showthread.php?t=37828
http://www.plctalk.net/qanda/attachment.ph...tachmentid=7906