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Question asked by eshaw on Aug 12, 2001
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN"><HTML><HEAD><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"><META NAME="Generator" CONTENT="MS Exchange Server version 5.5.2653.12"><TITLE>HPVEE MODBUS code</TITLE></HEAD><BODY><P><FONT SIZE=2 FACE="Arial">About 6 months ago we had to replace an broken oven microprocessor controller. The same controller was no longer available. So the person in charge picked out and purchased a replacement and just assumed there would only be slight code changes necessary for us to get it to work. When I received it I saw it didn't take the ASCII commands that worked with all our test software. I quickly got introduced to MODBUS. I had to extensively change the oven controlling section of the test software. What used to be a very simple I/O transaction is now much more complicated. The manufacturer of the controller who shall remain nameless was not a lot of help. Six months ago I found all the info I needed to understand MODBUS by searching on the web. I noticed now there seems to be more information on this subject surfacing.</FONT></P><P><FONT SIZE=2 FACE="Arial">Just last week I found a manufacturer that offers a free download of HPVEE MODBUS code. They do charge for the source code. </FONT></P><P><FONT SIZE=2 FACE="Arial"><A HREF="" TARGET="_blank"></A></FONT></P><P><FONT SIZE=2 FACE="Arial">The manufacturer of the controller I purchased said they went to MODBUS because it is a more reliable form of communications. I can see how it is more reliable but I never had a problem using the ASCII commands and simple I/O transactions in the past. All's it did for me was make me write a whole lot of new code. It was a fun challenge.</FONT></P><BR><P><FONT SIZE=2 FACE="Arial">Ed Shaw</FONT><BR><FONT SIZE=2 FACE="Arial">ATE Design Engineer</FONT></P><P><FONT SIZE=2 FACE="Arial">Comtech EFData Corporation</FONT><BR><FONT SIZE=2 FACE="Arial">2114 West Seventh Street</FONT><BR><FONT SIZE=2 FACE="Arial">Tempe, Arizona 85281</FONT><BR><FONT SIZE=2 FACE="Arial">Tel. 480-333-2107</FONT><BR><FONT SIZE=2 FACE="Arial">Fax 480-333-2161</FONT><BR><FONT SIZE=2 FACE="Arial">mailto:</FONT><FONT SIZE=2 FACE="Arial"></FONT><BR><FONT SIZE=2 FACE="Arial"><A HREF="" TARGET="_blank"></A></FONT></P><BR><BR><BR></BODY></HTML>