Craig

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Posts posted by Craig

  1. Posted

    If you are not controlling carbon rods to your reactor and you don't mind your control gear doing a bill gates on you then enet is fine. I would not touch it until it becomes scheduled and deterministic. Which is not likely. I guess eventually fast enet will be the norm, higher speed for enet is the only way around this. speed will prevail. Presently as soon as you mix with IT equipment you lose all reliablity and accountability for your control system. Losing your printer for half an hour is not the same as losing your process!!! The undeterministic nature of enet makes it a dog when comms errors begin to accumulate on your network. I presently ony use enet for non important stuff. It is a common trend to head enet way and also you see this with software, Revision after revision to fix bugs the IT way. Can you aford your control system to be like that. I think not.

  3. Posted

    I try to keep them brief, and use aliasing to real I/O as much as possible. Then even if you don't have a electrical schematic and are fault finding you still have some chance. I guess you probably know already but you can greatly improve program scan time and consistency if you alias the real I/O in control logix processors and use the alias throughout rather than the real I/O. You don't get hung up with RPI times this way.

  4. Posted · Edited by Craig

    Interesting discussion. I have used both and would say the omron is a dog and rslogix5000 will probably be alright by the time it gets to V20. Would choose rslogix over the omron everytime. Looking at your excel spreadsheet makes me frown the whole idea of rslogix5000 is to get away from using meaningless B registers and using usefully named bits and words. Should be able to put together a program that needs no additional descriptors other than the actual tags. In this way if someone ever uploads it they will still have a reasonable chance of figuring out what is happening.

  11. Posted

    I have a C200H cpu03 with an LK201 module which I want to commuciate via. Any Ideas what the settings in syswin need to be for this to work. IE baud rate etc the settings on the LK201 are sw1= 0 sw 2= 0 sw3= 5 sw 4= 2 I think the PLC is unit 8. Couldn't find this anywhere in the omron manuals. Thanks In advance. Regards Craig W

  13. Posted

    If you use the primary side the current ratio will be a lot less you can step them down even further by just using two CT's until you get to the right ratio. Your frequency of switching is going to be pretty high so normal ct's with iron cores will be no good you will need some with ferrite cores. At the high current you are talking about I would step down with the ct's then use an loop isolating transducer probably an optical one. as you don't want a mess. The current reading is probably not going to be that accurate as the SCR switching will produce alot of harmonics. AN easier way is just to take a look at what the firing rates for the SCR's are and calculate the RMS current from that and them make the big ASSUME from there.

  14. Posted

    I am pretty sure you will not be able to load a value into the present value tag the load preset bit is for loading a preset value into a different register in you HSC when your presentvalue exceeds the presetvalue a bit is set. There are 4 modes you can operate the HSC in and with some wiring you can freeze and hold the presentvalue and then restart and or reset it counting again. But not move a value into it. Suggest you reset it when required then start the count again.

  15. Posted

    Thanks Bob appreciate the advise from you and others. I didn't realise I needed to setup the PLC type etc. I am a newbie with omron PLC's. Guess I better read the manual first!!! Will go to the site tomorrow and hopefully get attached and upload. The default on my PC was a CV1000 so looks like this must be my problem. With Rockwell PLC's the descriptors etc are stored in an offline file is this the same with C200HS?

  16. Posted

    Thanks Nibroc, I got a usb unit from omron nz but still having a few problems I get an error saying "this command CV mode only " happens when I hit the test PLC button. I have tried a few slower baud rates but guess I should try 2400 as the PLC maybe older than 1995. ANy other thoughts on what could be wrong. Regards Craig W

  18. Posted

    Thanks for the info Nibroc, Yes I did mean Syswin. I will try omron for a USB convertor it has to be the problem have had similar problems with AB PLC's and USB converters.

  19. Posted

    I am using winsys and trying to connect via the serial port via a usb convertor to my laptop No joy at all any sugestions. Ihave the correct universal serail cable so just figure my USB convertor is the problem.