andepand

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About andepand

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  • Country Netherlands
  1. Hi everybody,For a while I’ve been wondering, in every plc forum where the use of loops come to discussion I find most people answering that it’s best to stay away from them and that there are better, easier and mostly less scan time demanding solutions out there. Why is that?In my experience they’re the next best thing.Why would referencing data from an array of 40 Dwords using a FOR X:= 0 TO 40 DO loop be any more scan time demanding then the PLC scanning through 40 rungs of statments?Just curious if I’m missing something here. Cheers
  2. Prv instruction in structured text

    Oh and btw, thanks Michael,  reading A 270 as a DINT made me recieve some numbers
  3. Prv instruction in structured text

    Maybe it’s a European thing  Like Michael said, in certain cases it’s very useful. In my current project for example, I work with large amounts ascii strings and data set in Lwords, which need to be shifted or moved and referenced in various ways Also I have remote in- and outputs from 40 individual stations for which I use arrays and lots of FOR TO loops and CASE statements  to make things easier to implement en modify.  In my opinion, once you get the hang of it the possibilities are endless and it’s much less time consuming to write, especially when using loops.
  4. Prv instruction in structured text

    Thanks for your input, I will check out your suggestion on monday  
  5. Hi, I can’t find an answer to the following and I was advised to ask it here.I’m programming an Omron CJ2M with an MD212 high speed I/O card. I usually do all my programming in Structured text, simply because I like it a lot over ladder or sft.Now, if I want to read the hight speed counter (incremental encoder), I have to make a ladder section and use the PRV instruction to store the present value in a chosen location.The manual says the current PV is stored in A271, but I can’t get a readout there. Apparently the only way to read it is through this instruction.Does anyone know if there is an equivalent to the PRV instruction for Structured text? or another way perhaps? Again, when I check the actual memory adress, there’s no value there withouth the use of the PRV instr.
  6. Ethernet/IP bandwidth

    I’ve decided to just try, in my opinion not alot of information is exchanged even by the vision system. If I run into any trouble I’ll be back. thanks, Andy
  7. Ethernet/IP bandwidth

    Hello, A while ago I modernised a magazine gathering / filmwrapping machine. This was a fairly big project for which I used an Omron CJ2M as the main PLC, 10 Wago Ethernet/IP fieldbus couplers, a Keyence CV-X420 vision camera and an Omron NS12 HMI.  All of these components run on the same network which contains an unmanaged switch where the HMI, PLC and the first Wago are connected. The Wago’s act as a two port switch since they are all daisy chained. At the end of the Wago chain there is also the vision cam which is connected at the last Wago coupler. At the time I was advised against using Broadcasting instead of Multicasting with a managed switch, but I tried anyway since my networking knowlege is lacking. Also, the only ‘bandwidth demanding data’ comes from the vision system. The Wago couplers contain only digital I/O and high speed encoder inputs run directly to the CJ2M. I haven’t run into any trouble so far and the machine is already producing for over a year. Now , a new project is on the way and it will need even more Ethernet couplers, 15 to be precise.  This brings me to my question; is there a limit to the number of nodes in an Ethernet/IP network and will I possibly run in to bandwidth problems by adding more remote I/O and not using a mannaged switch? Also, I would like to get high speed input out of one of the Wago couplers. Thanks in advance for any feedback! Greetings from Holland Andy 
  8. Remote I/O refresh problem

    I’m sure. I set up a pulse check ladder, the main pulse (direct input to the Omron, so no problems there) has a two step counter which is reset every cycle by the pulses from the network nodes. On very low machine speeds, all is fine, at higher speeds (still the sensors are set for half a second) these problems occur and my pulse counter runs to zero. I could make the pulses longer by lengthening the cam which switches the proximity sensor, but I feel that doesn’t solve my problems.
  9. Remote I/O refresh problem

    Hi all, I’m having some problems regarding a digital input from a remote ethernet coupler input. My setup contais an Omron CJ2M cpu33, a switch, an Omron NS5 HMI (also ethernet) and 10 Wago Ethernet/IP couplers, all of which have 2 digital in- and 2 digital output cards. Every machine cycle all couplers recieve an input from a regulair proximity switch, this signal is high for about half a second and switches at a frequency of about every 2 seconds. Despite the fact there’s no high speed stuff going on here, the pulses are not processed properly. Monitoring my program I can see that the inputs are skipped and somtimes are not processed even for several machine cycles. Is my network too slow, can it be a scan time issue, or something else. I’ve come a long way building this system but I’m still fairly new to plc programming. Hope someone has a suggestion. Best regards,   Andy      
  10. Omron CJ2M - Wago remote I/O

    Hi there, I’m not sure how familiar most of you are with Wago remote I/O, but I hope you may have some solution for the following connection problem I’m having. I’m working on a project to modernise an old folder collecting machine for which I’m using an Omron CJ2M Cpu33 together with 8 Wago 750-352 remote I/O units over ethernet/ip. These Wago units all contain two 8DI digital input cards and two 8DO digital output cards alongside a 750-610 bus power supply card. Adding them to my network in CX network manager is no problem and all seems to work fine. That is, as long as I don’t physically add the bus power supply card, which I need to, well.. power the Wago bus. Soon as I add this card (which was in place while making all the necessary settings to the Wago and Omron units) it just won’t connect. Remove it and it connects like it should. As far as I know the power supply card has no I/O addresses or other communication functions whatsoever, so I can’t get my head around it. Even stranger is that when instead of it I add an analog input card, with bus power connections build in, it connects without a problem. The .eds file only contains info about the main Wago unit, after installing it I should be able to add any kind of I/O card and address them in the Omron software. Also, the supply card is added and visible as a fifth card in the Wago I/O settings and the I/O status led is green during this error. Therefore I would say the problem is at the Omron side. Any sugestions?   Thanks in advance Andy - The Netherlands