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Need help...

I have a system using a TSX87 PLC, Monitor77 as a HMI software (DOS Version) and Unitelway as a protocol to communicate... I'm also using a Pentium 1 PC and Quarterdeck Expanded Memory Manager. Now the system is running well, but I want to upgrade an old PC that I used with 3 GHz Pentium-D PC. I just reconfigured the config.sys and autoexec.bat file to load a monitor77 application (running well) but the comunication between my new PC and my PLC is error (it says "slave:15 busy".

Is that because I'm using a dual core processor or something else? Please send me an email if any one of you in this forum can help me solving my problem... Thx.

Your communication error has more to do with timing issues. When these old DOS programs where designed, speeds were well below 166MHz. The faster PCs of today have much extremely higher clock speeds which interfere with communications and give you timing issues with throughput.

You'll need to stay with motherboards below 450MHz to resolve your communications issues.

Robert Stanton

What version of the Unitelway Driver are you using?