adccommunitymod (AutomationDirect) asked a question.
Created Date: September 05,2013
Created By: bcarlton
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Just another warning about documentation. I have a program which is continually sending the accumulator contents to a group of 'C ' bits using OUT VC60 (which overwrites bits C60 through C77). The part of the accumulator which was overwriting the C70 - C77 bits would always be zeros. Of course, foolishly ignoring my own practice, I didn't individually annotate C60-C77 about this usage. Later (about ten years later actually) I used the program in a nearly identical application. During modification I decided I needed to use a couple of new bits and used C70 and C71 (which obviously were free because there was no bit documentation - right?) It drove me nuts trying to figure out why the bits (which would be written by the HMI) weren't turning on. And 'Find ' didn't find any other uses of these bits. The Xref didn't show anything either. I finally stumbled on the other (now not needed incidentally) section of code doing the 'OUT VC60 '. So another sheepish moment which I share as a warning.
Created Date: September 05,2013
Created by: pressgrove
I 've run into similar problems using TMRA instructions. I now write "DO NOT USE " in all of the element and word descriptions that are affected.
Created Date: September 06,2013
Created by: KB1GNI
I 've been bitten in a similar fashion before - I make it a habit now to annotate all locations like that with "Used ".
Double precision instructions that use two adjacent V-memory registers are another one that will get you if you 're not careful.
Created Date: September 06,2013
Created by: Adisharr
Sounds like another addition to the next version of Directsoft. I 've done that a few times in my Omron days as well.
Has anyone else here ever had the pleasure of using Omron's LSS? That had one of the worst commenting systems I 've ever seen in ladder software.
Created Date: September 06,2013
Created by: bcarlton
At least with TMRA instructions (eg TMRA T0 K100) if you search for the following timer number (T1) the 'Find ' will stop at the TMRA - T0 instruction. The XRef will note T1's use also.
I'm not suggesting that the utilized 'C ' bits in my example should have been found by the Find or XRef (though it would be nice - but probably very difficult). It's just that I should have followed my own custom of documenting. I was too used to being able to also determine usage by the negative results of the 'Find '.
Created Date: September 06,2013
Created by: BobO
At the risk of being annoying with my unabashed bias, Do-more solves most of this. ;)
Created Date: September 05,2013
Created by: bcarlton
Just another warning about documentation.
I have a program which is continually sending the accumulator contents to a group of 'C ' bits using OUT VC60 (which overwrites bits C60 through C77). The part of the accumulator which was overwriting the C70 - C77 bits would always be zeros.
Of course, foolishly ignoring my own practice, I didn't individually annotate C60-C77 about this usage.
Later (about ten years later actually) I used the program in a nearly identical application. During modification I decided I needed to use a couple of new bits and used C70 and C71 (which obviously were free because there was no bit documentation - right?)
It drove me nuts trying to figure out why the bits (which would be written by the HMI) weren't turning on. And 'Find ' didn't find any other uses of these bits. The Xref didn't show anything either. I finally stumbled on the other (now not needed incidentally) section of code doing the 'OUT VC60 '.
So another sheepish moment which I share as a warning.