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About mellis

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  1. MOVs To Protect Outputs

    I'm with vettedrivr on this one. A diode across the 24vdc relay coil will do fine. MOVs are normally used on 120VAC inductive loads. Diodes are normally used on 24VDC inductive loads regardless of whether the output is a transistor or a relay contact.
  2. Pulse an output

    I agree. If you want to control the extend speed, this is the traditional way to do it. If you need full speed extend in some cases and a slow extend too, then a 2-way solenoid in parallel with the flow control should do the trick. Pick a NO or NC solenoid to suit your preferred failure mode.
  3. PLC5 Emulator

    Check "Limitations of the Software" under the help on Emulate5. Bottom line, The MSG instruction doesn't actually work in Emulate5.
  4. How to change many machines easily

    The idea of scripting online program changes makes me a bit uncomfortable... (Nothing could possibly go wrong with that) Yes, it's a tedious process to make repetitive changes. You have a few options. First, if you can make the changes by downloading rather than on-line then you may be interested in one of the PLC management programs. With one of these systems, you can replace the "Official" offline version of each PLC program and the management program will take care of downloading the updates when it "checks" the online version and finds that it is different.. However, if you need to do the updates online you still can make it as painless as possible. Minimize the keystrokes and the potential for errors my running two RSLogix500 sessions. One open with the updated program and one on-line with the current target. Use cut and paste to make the changes. The key here is to make as few cut and pastes as possible. Sometimes it is easier to cut and paste the entire contents of the program file rather than just the rungs that changed. Note that you won't be able to do this if you are real tight on memory. Make a checklist of the processors to update and check each one off as you complete it. This will be a big help when someone inevitably interrupts you in the middle of this process. If you have a partner working with you, make it their job to intercept people who want to interrrupt you. The key thing here is to ensure it gets done reliably. Good luck,
  5. MVI56-MCM

    The manual is a bit daunting. The sample program takes care of copying data to and from the MVI56-MCM. You have to set up the command list for your particular device. However, Prosoft's tech support is excellent. I'd recommend you take a shot at configuring the command list for your device and then call Prosoft and have them walk you through it and see what you missed. There is even a chance they are familiar with the device you are talking to. They were very helpful to me when I used the MVI56-MCM the first time. Good luck,
  6. Anyone here purchase the OEM Toolkit?

    When you run the EVMove untility, it defaults to transferring one of every license available. What you want to do is select the "Edit All" button and change the quantity to 0. Then, select the license you want to transfer and select the "Edit Selected" button and change the quantity to 1. Now you can finally select the "Move" button and transfer your license. Good luck,
  7. Home plc software help

    The way I solved this problem is pretty simple. My work computer was replaced with a notebook. Now I can use the same software that I use in the office when I am in the plant, at home, or travelling. To the best of my knowledge, there is no editor for ControlLogix other than RSLogix5000. However, there is a way to edit ControlLogix programs as regular text files (actually XML). You save the file as an L5K file instead of an ACD file. This file you can edit without RSLogix. Many people use this method to produce repetitive code quickly. I have seen Excel spreadsheets with macros and even SQL databases produce entire or partial L5K files. I don't think that was exactly what you were looking for, but it might be useful. Good luck,
  8. From my point of view there are two entirely separate questions here. 1) Should you run 4 production lines from the same controller? 2) Should you use a redundant controller? I would highly recommend that any production line that can run independantly deserves its own controller. Putting all 4 lines at risk everytime you make a change is reason enough to separate them. Single point of failure for all 4 lines is bad too. Performance is another reason. Unless the processor demands of your lines are trivial, sharing a processor imposes limits on performance as well. Controller failure is an extemely rare thing. Why is it that most people start thinking of improving the reliablility of a control system by making one of the most reliable parts redundant? If that is all you do, it usually has the opposite effect (more failure points, more failure modes, etc.). I've seem some strange things done in the name of redundancy. Another point that is important is that redundancy takes some of the performance of your processor away from the application. Keeping both processors memory synched takes processor resources. So a redundant pair of processors is actually less capable of running mulitple lines than a single processor of the same model. Bottom line, I'd recommend 4 single processors for your 4 production lines. If any of the lines are so mission critical that you really need zero downtime, then each one of those systems deserves its own robust design. That may include redundant processors, but it would also include redundant power supplies, networks, and I/O.
  9. Moving two PLC5 projects into one CLX processor

    Wildswing, As long as you put the I/O for the two PLC5s on two separate networks, you won't have any issues with duplicate I/O addresses. I'd recommend two CNB modules in the CLX processor rack, one for each system. Two programs in the CLX will contain the two PLC5 progams. If you have any STIs, they go into periodic tasks. It's not that big a task. You can work outside the RSLogix5000 environment like Bob suggested (I've done it and it can be very helpful). But you can convert both programs, add a prefix to the tags in each program to identify both systems, and eliminate any possibility of tag duplication. The ability to cut and paste of the entire contents of a program file make the merge pretty easy. I still think you should redo the tag names after conversion, but that's a documentation and support issue more than a functional one. If there was a reason for using L type (extended local) processors in the first place, I'd be very careful about using RIO. Good luck,
  10. RSLogix DH-485 Node changing

    In RSLogix500, under the controller tab, is "Channel Configuration". Double click it and a dialog box will open will all the settings you need. Good luck,
  11. SLC Data Collection

    Bob, FYI, the 1756-ENET isn't really available for sale anymore. The 1756-ENBT replaces it. (The web page gives "invalid catalog number" when you try to put it in cart)
  12. What is the area classification? (i.e. Class I, Group D, Division 2) The solution will vary depending on the area classification.
  13. PLC5 read from Logix 5000

    OK, here goes... Logic processor to back plane to DHRIO in slot 2. 1,2, Out channel B to node 70 on DH+ (Is that octal or decimal node number? The example below is correct for decimal) 3, 70, Node 70 is apparently another DHRIO card in a different chassis. That chassis has two DHRIO cards which are nodes on two different DH+ networks. To backplane to DHRIO in slot 3. 1,3, Out channel B to node 35 on DH+ (Once again, is that octal or decimal node number?) 3, 35 I've never attempted to bridge DH+ networks like this, so I can't say for certain this will work but it does follow the routing rules. I know you can bridge DH+ networks with PLC-5s and that you need link IDs for that.
  14. RSViewME / SE and efficient comms

    If you are really looking to optimize, create a DINT array. You can directly reference bits or words in the array in your code or you can alias to bits or words in the array. The key points are to use the native word size of the ControlLogix (DINT) like newpageboba said. And to keep all your data in a contiguous area of memory. The way you do that in a ControlLogix is an array. Good luck,

    I believe that it is 8:00 am to 5:00 pm local for the time zone of the site that purchased the contract. If you need support for all time zones, there is 24/7 support available as an option (at added cost). My company uses the 8:00 am to 5:00 pm support.