Most robust, industrial PLC

[gravitar 3]

"Which is the best" posts always become emotional sooner or later. I'm surprised it took 24 replies!

[BobB 58]

I have deliberatly stayed out of this for a long time. These things always become emotive unfortunately. I will kick in with a little bit and this is not emotive stuff, just my experiences. I have had problems with Hitachi power supplies on the few jobs where I have used them and also with some noise problems as well. The noise problems were not with I/O because all inputs were wired in screened cable. The problem was noise into the processor or insufficient filtering in the power supply. I mainly use Omron and have had a few problems over many years with capacitors drying out in power supplies and have found the same problem with all other brands that I have used over a period of time. By the way, I have probably used close to 1000 Omron's and the power supply problem would be less than 1% over 20 years. That is very good considering some of the places they operate. I have found Omron power supplies are particularly resistant to industrial noise and have never had a problem with noise getting into a processor. I have not used a lot of Siemens and have not had any problems with them but have never used them in a noisy industrial environment. I have had problems with AB SLC racks from time to time but so have many others from what I have seen on various web sites. I have not had any problems with Mitsubishi but have not installed any of them in a noisy industrial environment. I have had problems with GE-Fanuc 90-30 processors locking up around diesel generator installations. Worse still, the last time I took one out I sent it to the local distributor and it took them 6 months to send the unit back, charged me heaps and told me there was nothing wrong with it. The new processor I purchased, at quite a high price, is still working OK. Another thing that should be taken into consideration is where the PLC is to operate. I have seen PLCs with a maximum operating temperature of 50 deg c operating in areas that were quite a bit hotter than that. Then the client complains when the PLC fails. Take note of the environmental limits described by the PLC manufacturer. With respect to easy to use etc, this is in the eye of the beholder. I dislike Siemens immensely but for those brought up on Siemens they love them. It depends on how you like to program etc and where you are comfortable. Siemens PLCs appear to work much more like a straight microprocessor and most/all Siemens users program with STL. I do not like STL because I have not been brought up with it but given time would probably get to like it because it can perform some very complex functions (written by the user) very efficiently, far more efficiently than ladder usually. It is a matter of understanding. I do not like Mitsubishi software much either but know quite a few who do. I do like Omron software immensely as I can program key combinations to the way I want to work. I dislike using mice and getting RSI dropping and dragging FBs all over the place. I much prefer to use the keyboard, but that is my prefernce and I will not knock someone else for wanting to program with another set of software because that is their comfort zone or preference. The software for the Schneider Twido is abominable in my view but some like it. I stopped using the Twido after 2 jobs because of the software. Shame really because it is fine for some smaller jobs. I could go down the list of all the PLCs I have ever used but really it is pointless. People will usually pump for their favourite brand (usually because they are in a comfort zone there) and most of us are "under the pump" trying to get a job out in a hurry. Consequently we do not have enough time to learn new PLCs/software. Given the choice we would all probably stay in our comfort zone unless pressed to use a different brand or have to find a solution from another manufacturer because our favourite brand had difficulty in performing the job at hand for whatever reason.

[Sleepy Wombat 27]

[rpraveenkum 5]

Delete delete the character after the caret Enter edit the current field Esc cancel the current action, including a mouse drag Right/Left arrow open/close the current folder (+/- folder toggle) in the Controller Organizer, or navigate to the left or right in the various editors/browsers Space bring up context-sensitive menus (this is the same as a right mouse click) in the Controller Organizer Tab advance the cursor forward through a dialog’s fields or buttons Up/Down arrow navigate up and down in the various editors/browsers F1 launch help F2 edit the current field F3 find the next search result F4 navigate to the next error in the Output window's error list. This is an alternative to double clicking on the errors in the Output window. By repeatedly pressing F4, you can navigate through all errors in the list. A useful trick is to hide the Output window, to reclaim the screen real estate it takes, and to use F4 to navigate through the errors. You can fix them as you go, or use F4 and shift-F4 to move back and forth through the list as you need to. The current error message will be displayed on the status bar, so you lose nothing with this approach. F6 toggle between ladder editor panes Alt + ¯ access dropdown browsers/editors Alt + F locate the cursor on the File option on the main menu Alt + E locate the cursor on the Edit option on the main menu Alt + V locate the cursor on the View option on the main menu Alt + S locate the cursor on the Search option on the main menu Alt + L locate the cursor on the Logic option on the main menu Alt + C locate the cursor on the Communications option on the main menu Alt + T locate the cursor on the Tools option on the main menu Alt + W locate the cursor on the Window option on the main menu Alt + H locate the cursor on the Help option on the main menu Alt + Enter bring up the properties for the active routine Alt + Insert bring up the appropriate Add Language Element dialog Alt + Tab switch between all running applications Alt + - (hyphen) access the View menu, from which you can move or resize the view Alt + 0 toggle the Controller Organizer window Alt + 1 toggle the Output window Alt + F4 close the application in focus Ctrl + Enter apply modifications to element comment (Ladder Editor only) Ctrl + PageDown move to the next tab in a dialog or routine window Ctrl + PageUp move to the previous tab in a dialog or routine window Ctrl + Tab move between multiple views (e.g., Ladder Editor, Tag Editor, etc.) Ctrl + C perform a copy Ctrl + D edit a description Ctrl + E navigate to cross reference Ctrl + F bring up the Find dialog Ctrl + G bring up the Go To dialog Ctrl + H bring up the Replace dialog Ctrl + I toggle between insert and append modes Ctrl + N create a new controller Ctrl + O open a controller Ctrl + P access the Print dialog Ctrl + R insert a rung Ctrl + S save a controller Ctrl + T toggle the bit Ctrl + V perform a paste Ctrl + W access the New Tag dialog, from which you can add a new tag Ctrl + X perform a cut Ctrl + Y perform a redo Ctrl + Z perform an undo Ctrl + F4 close the window in focus Ctrl + F6 toggle between multiple views (e.g., Ladder Editor, Tag Editor, etc.) Shift + Tab move the cursor backward through a dialog’s fields or buttons Shift + F3 find the previous search result Shift + F4 navigate to the location in which the previous error occurred in the ladder, or navigate to the previous error in the Output window's error list Shift + F10 bring up context-sensitive menus (this is the same as a right mouse click) Shift + Ctrl + Tab move between multiple views in the opposite direction from Ctrl+Tab

[Sleepy Wombat 27]

ravpravenkum, I am still trying to work out the purpose of your last post....

[JesperMP 2]

I have to respond to that I am not easy going. Sorry if it is little late.Actually I think that my 1st post is a logical reply to Plastic Dude's original question about reliability and noise resistance. However your 1st post is an illogical comment about upgradability. I posted a remark about that, that is all. You however has refrained from responding to that comment, but has in stead continued about me being not awake. Hmmmm... Maybe I am not so easygoing. Some other times I have gotten comments about being unemotional. I think that is because of two things: 1. To logically phrased technical questions, you should answer logically and to the point. 2. It is probably a language thing. Wit and sarkasm does not transport well over languages or a web page. I actually love a good joke or a good fight for that matter.

[BITS N BYTES 66]

MAN - Do U need to lighten up. Here are some Danish jokes to help U. Interpol was looking for an escaped convict in Denmark, and sent pictures of the man to the Danish police. The pictures were taken from both sides and the front. After a few days the Danes replied: "We caught the guys on the left and the right but the one in the middle got away". Q: Why do Danish people never play hide and seek? A: Nobody wants to look for them. A Danish airplane was getting ready to land in Stockholm's airport. The control tower contacted the pilot and asked for his position. The Danish pilot was surprised and didn't do anything. Again the control tower contacted the pilot. "Please tell us your position." Then the pilot understood and answered: "Here I am in the front seat, as always..." 1: Do you know how to find a lost Dane? 2: No 1: Good!

[interruptedz 0]

i've been programming the german way since out of college.and tried other japanese plcs.all i can say is german style of programming is easy to debug and organize.and some parts of the code are reusable to other projects.you just have to make it global.it uses subroutine,just like in c++. The only thing i hate abt them is expensive.