Been Around

Dosen't this refer to: basically The MCR instruction is not a substitute for a hard-wired master control relay that provides emergency-stop capability. You should still install a hard-wired master control relay to provide emergency I/O power shutdown. and Allen Bradley Bulletin 1882 copyright 1982 WARNING: A PC system should not be operated without a hard-wired Master Con- trol Relay and Emergency Stop Switches to provide emergency I/O power shut down. Emergency Stops can br moni- tored but should NOT be controlled by the User Program. These devices should be wired as describe in tle PLC-2/20 As- sembly and Instruction Manual (Publica- tion 1772-801). This is direct quote from manual page 7-1 CAPITALS and all Being said it was ignored for years.

noope

Yea, Exactly right. It's good to see someone with the grip on this subject. Sometimes too much info is a bad thing. And the ability to know the difference is priceless. I can see the day when newer programmers do not even consider actual process, just as we could not consider spell checkers. Our spell checkers were teachers!!! I have spent many hours documenting programs that will never be read by anyone. As well dechipring programs with no docs. Just like the best weld you will ever make no one will ever see. That's the way folks need to consider programming. Program it where anyone with a little sense can understand. Sometimes this makes your program longer. Oh well. Thats why I feel : He who does the most with the least is the best is a relative statement. It all is relative to process and understanding. NOT only programmer, but people that will excetute control system. A system is no good if it can't be implemeted, don't care who writes it

Why Would You keep your thinking from operator? My guess would be too much information for operator !! Been there Yes, There are many ways to doc. But there are no greater rescources than an operator. It's been fun today, I visited here and actually wrote some code today WOW I got something acomplished without a spell check. good luck to who reads my docs today!!!

OK I assume your talking AB, (being in this forum) One of the great strides in programming was RSlogix storing all comments within one program file.. Those of us that grew with plc-2, plc5,AI series and Icom software. (as well as westinghouse, modicon,GE, SLC,Cutler-Hammer, Omrion and ever other plc). Walking in a new plant was a challenge, not a nightmare. Most of us presumed we would not have any docs. Heck, Most of us were upgrading from hardwire. We did not have many if any hard wire schematics. Much less plc inputs/outputs!. We had to rely on our understanding of machine process and our facination of controllers. Trying to make a living and follow the knowledge and understanding that processors were the way for controls. I just started on a new process and can't learn enougt My have things have changed. If you do not have docs, its not the end of world. Understand the process, Heck, any number of people can explain the steps to programming software. They teach it everday. But no one can teach you the ability to look at a process and know that you understand how it works and how to program it. That is a gift that you must explore. The best way to learn a new process is to talk to operators!!!. They will tell you 99 percent of the problems with machine and 100 percent of what is wrong with your controls. As to your first question, There is a way and many ways to store comments on a PLC. But you must know HOW TO STORE IT,where it is stored, how it is stored and how to read it. The wonderful ability of controls is the many ways to do something. Always ask yourself, DO I UNDERSTAND WHAT WE ARE DOING! Regardless If I am a programmer, operator, welder, electrician, supervisor or laborer. Look at programming from every aspect. If you are the laborer how can I safely help them If you are the laborer, how can I safely help them If you are the welder, how can I safely help them If you are the electrician, how can I safely help them If you are the supervisor how can I help them any!! understand, The programmer's understanding and ability is the heart of any controls.With that said, It takes common sense and experience to be a welder, electrician, maybe supervisors (ha-ha), and laborers, yes, most folks with any sense dont stay in laborers, but I have seen many intelligent laborers. Remember, All the above can operate without ant controls, but you can't operate without them installing and running equipment TWControls I really don't know but planning to find out! Boy, I have to work on my typing without a spell checker. I guess I could proofread more!

Allen Bradley Bulletin 1882 copyright 1982 WARNING: A PC system should not be operated without a hard-wired Master Con- trol Relay and Emergency Stop Switches to provide emergency I/O power shut down. Emergency Stops can br moni- tored but should NOT be controlled by the User Program. These devices should be wired as describe in tle PLC-2/20 As- sembly and Instruction Manual (Publica- tion 1772-801). This is direct quote from manual page 7-1 CAPITALS and all Being said it was ignored for years. One of my fathers quotes: If carpenters build houses the way some programmers wrote programs, the first woodpecker that came along, would destroy civilization as we know it I wish I could type as good as I reed!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!1

jfls41 TWControls is exactly right. Years ago when I started it was industry standard to use MCR in program to stop all machine functions. It was practiced that as long as the plc did not see e-stop, or did see, people relied on plc not to energize any real word outputs. Unfortunately some people had to die before laws were enacted to guard from this. You could input contacts from estop as insurance to stop plc from execututing any real world functions or for data acquisition. I don't use MCRs much anymore. I just looked at some of my old plc/2 files and confirmed that we did use to use MCRs as e-stops. Not just us but alot of different programs by different vendors. MCRs works good to: stop section of program so you can look at registers later. ( brfore good and inexpensive data acqusition software became available). Keep sections from performing math functions On some batch files When memory is tight. ( that's not the case these days) And as a backup safety device. ( IF ONLY IN THE MIND) AS TWCONTROLS SAID,, PLC IS NOT A SAFETY DEVICE !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! I don't believe you will have the need for many MCRs. ( unless it's a vintage instructor stuck on logic in there period) As for presses, I have never needed a contact off a MCR, just looked at logic making MCR true. If you try to monitor state of MCR in progam you will not get any results as to the MCR pausing program. I have and still do work on a few presses. What I have found with redundant PLC is to check yourself. You know even safety PLCs are electronic devices. What else could you install on it that is not electronics. OSHA has no choice but to come up with a central ground to try to make different situtations as safe a possible. With a machine that has only hard wire or simple controls its easy to design components for fail safe. Presses are different. You have to monitor pressure, what with? Electronics. What else could be relied on to stop pressure from building? Or determing pressure drop.? Good luck with project. I hope this has helped some. I'm sure theres alot of discussion you can get on this subject. I look foward to reading replies. Also, MRC Means Master Control Relay If only our PLC founding fathers would have known that safety has become the forefront of controls, do you think they would have put so much time on MCRs to stop sections of logic? Is that not we use program files for ? Wow.

How did it go? Learn anything? best of luck in programming!

Yes it's a passion. I truly enjoy controls. I've been around some kind of controls since 1983. Had a good teacher. My father and experience. Seen alot of changes in plc's over the years. Theres not much of a better time to be in controls. Not to many years ago there was no support. I remember many times just a manual and enthuasism. This is a good forum, lots of good reading, no lack of opposing views. Although it seems everyone has the bug and honestly tries to give good information. Good luck with programming. You need turn your computer occasionally OK, We got off the subject of Boblfoot, Sorry. I have never seen a 5/40 do this. did have a couple of 5/15s and a 5/25. Sent off and had repaired. Mickey, if your ever board (right) try this classic site http://blueballfixed.ytmnd.com/

Ok, Can't say enough good about realibity of these. I have taken a 5 just as you describle and shorted volitle chips on board and revived. It was a trick learn years ago. Be careful, although plc is dead anyway. haven't work in all situtations but plc5 in my demostrator here just powererd up after I revived it over 5 years ago. I test alot of programming and electronics with it. You know I have it bad, plc at home. actually 3 plc5/25

Yes sir, Been there. but a 100 plc'sssssssssssssssssssssssss

Man that's great, you must be in like plc, programming, troubleshooting ....... HEAVEN!

Boblfoot, Thats great performance for 100 plc's. The PLC-5 is a great processor. not just now, but for a long time. They are tanks. I have replace 62,535 slc's before plc5 for power issues(ha-ha) no, but alot more You do keep a spare? im sure. Maybe that processor went out OGK Keep up great posts!

Wally96 when I turned on the surge protector I bobbled the switch on and off a few times, and faulted the processor for good. Do not do that again!! Grounding is key on ML, Torque those screws. You might try battery backup for ML power. Not on commons for outputs, just processor. I have found that helps considerbally. Just has to be labeled. Good Luck

Boblfoot right on. Also, can you picture this process in your mind? That is where it starts, study and understand the process and the rest is well, : study design study program study install study test study troubleshoot study startup study troubleshoot troubleshoot study repeat I know I have left out 99% Best of luck!!

Does anyone know how to disable feature in outlook express asking if it ok to send email? Any help would be greatly appreciated!!

also, you could use a seperate set of contacts from local/remote ss to power visual and/or audiable alarm that would be very hard to ignore. Or send signal to control room that will alarm or notify after a period of time in manual.. If you cant trust your operators to remember to change state of ss, It would not be wise to trust control system to hope no one is is physical danger. I have used manualmatic before, but only if operator cannot be placed in harms way. If system is that critical, maybe wait for period of time before auto switching into remote.(only after notifying with pause before starting) too bad we cant program operators SAFETY FIRST Could operator hold spring return pushbutton while calibrating??

Your quite right. thanks for moving post.I usually spend more time reading before I ask for help. You might have noticed this was my first post. It is helpful and a pleasure to go to a forum and only see posts that relate to a certain subject. this save alot of time. I do understand I have seen the error of my ways. Knowledge with understanding is a plus Thank you again, Happy Programming

Because I figured that as a general rule someone using messenger would have used outlook express also. maybe not? I do not know of any forums for outlook express, maybe I didnt do enough research on mr.plc. Sorry for misunderstanding. I will be more careful ! Thanks for this site. If I never asked another question its still good reading on diversity of applications being discussed. I have been troubleshooting and programming since my late father and I started controls business in 1983. and im only 39 years old. I have seen alot of diversity through various companies over the years. As well as alot of people trying to program. Anyhow, I fixed this problem, but it shouldnt have been if I would have spent more time reading or at least paying attention when I read it first !!!!! Again, Thank you

sorry, but it did pertain to ab

OK, Thanks for information, on my other question I figured it out. I read settings in express, but did not see. Just read to fast. Allright in outlook express tools options security Warn me when another program tries to send email as me. That wasnt hard. dop! Well it was worth posting and reading today, good to see other people who eats and sleeps controls!

Also, could someone tell me how to take off new user below pic?

Does anyone know how to disable feature in outlook express asking if it ok to send email? Any help would be greatly appreciated!! I thought I posted this in AB to start with