Ken Roach

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About Ken Roach

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  1. Flex I/O Rack

    Download and read the 1794 FLEX I/O Selection Guide.    It will show you the basics of which terminal modules go with which I/O modules, and how power is calculated and provided.
  2. Allen Bradley + Profibus

    It's just a matter of which protocols are championed by the market leaders in their area.     Profibus has deep ties to Siemens, and the risks of integrating Profibus directly into their controllers outweighs the technical and market penetration benefits. Even though Profibus is in theory an independent technology not controlled by Siemens, they still control the source of good interface chips.  What if they restricted Rockwell from buying them ?   What if they asserted a patent, even without good grounds to do so ?  It's happened before (the Solaia/Schneider affair). And at the product level, Rockwell's never going to have easy, smooth, simple integration with Profibus like Siemens does.   So offering Profibus integrated into their controllers pretty much would start out with "Siemens does this better than we do". There's also a matter of competitive differentiation.    Rockwell had ControlNet and DeviceNet and EtherNet/IP, and promotes those in competition with Profibus and ProfiNet.    To adopt Profibus wholeheartedly would give up a major competitive differentiator in which they'd invested many years and many dollars. I have a Hilscher NT100 bridge on my desk between EtherNet/IP and Profibus DP.    I'm not sure that a built-in Profibus DP scanner in the ControlLogix would be a lot easier to use, if it existed.
  3. I2C Communication

    If your microcontroller-based device used SPI or another low-level interface like a shift-register or parallel discrete interface, then the HMS brick or module implementation of their CompactCom NP40 chip would be ideal: Hilscher is also a leader in embedded board levels stuff.   I'm working with their relatively-bigger NT100 units this month, but they also make board-level products
  4. FT View ME Datalog

    Where are you seeing information about "switching from one to the other" ? In general, FactoryTalk View ME allows you to run only one "Data Log Model".     It polls and stores all the data that will be used for Trends and for Data Logs in the project. It is one of the weakest features of FactoryTalk View ME.
  5. The Rockwell Automation PLC platforms have never supported that sort of functionality.  I's something that Siemens is very proud of, but of course you need to very carefully designate and monitor that data area. A popular workaround is to use a Rockwell utility to upload specific data registers, then perform your program download, then restore the values of those registers. There's one called the "Data Preserve Download Tool" that's for ControlLogix family controllers (v13 and up), and another general purpose data upload/download tool called the "Tag Upload Download Tool" that works with MicroLogix, and PLC/SLC controllers.   The Tag Upload/Download Tool does use the OPC Automation Interface, so you need an OPC-capable license (anything but Lite) for RSLinx Classic to use it.
  6. Communicating with old panelview plus

    You've identified that the basic problem is that RSLinx Enterprise doesn't recognize the newest controllers, so you can't create a Shortcut from the normal browsing method. The first thing I'd try is to manually enter an old 1756-L6x controller into the RSLinx Enterprise schema, as though it was in Slot 0 of a 1756 chassis. If that doesn't work, I agree that an upgraded copy of FTView Studio is probably appropriate, with a *.MER compiled to run on v5.x firmware.
  7. Display IP Address

    I've done it a handful of times.   I usually don't use the UDT that they use as an example, and forget to make my target data array big enough, but it definitely works. If you want to copy your code into a simplified application and post it, I've got a 1756-L71 and a 1756-EN2T I can test it on.
  8. Display IP Address

    You can send a CIP Generic message to the TCP/IP Object in the 1756-EN2T itself to get the IP configuration. It's documented in the RA Knowledgebase;   Article ID #26779 (TechConnect required).
  9. PV+ Export Alarm History to USB external memory

    It's not particularly easy, but it's possible. What you need are the files associated with the Alarm History, as well as the files that describe the Alarm Configuration, and you run those both through a FactoryTalk log file viewer utility. Whenever I do this, I get out and pay close attention to the directions in this Knowledgebase article: And then I say nasty things about the parents of the FactoryTalk View developers, and go back to using Indusoft where my alarms are logged into an SQL database.
  10. PV 800 and Camera

    I don't think so.   The PanelView 800 is the lowest-end product in the A-B HMI range and I've never seen an ActiveX or a Browser object for it. I know there's limited support for Cognex camera objects, and the Browser object will allow some webcams to work, with the PanelView Plus 6 and Plus 7 Performance model HMIs.
  11. Kinetix 300 Hard Limits

    Are we talking about a Kinetix 350, or a Kinetix 300 ? The 300 has the browser/java configuration interface and is a standalone or treated-as-an-IO-adapter device with ControlLogix. The 350 works as a CIP Motion axis, and is configured entirely within Studio 5000 Logix Designer.   That's the one you would use a Motion Servo On (MSO) instruction on. I installed four Kinetix 350's on a project where I had no hardwired overtravels, and had to use CIP MSG instructions to turn off the Overtravel feature (it's stored in NVRAM so it's permanent unless you load new firmware).   I just made those MSG instructions something we toggled once when setting up the machine.  
  12. 1738-IT2IM12 thermocouple wiring - compensating cable

    Not to mention the cold junction offset values !    That is meant to be used as a substitute for the CJC devices themselves;  you're supposed to put the estimated temperature at the module in there, and un-check the CJC box.    Your temperature isn't off by 10 degrees;  it's off by 40. You need proper thermocouple extension cable if this system is going to get anywhere near accurate measurements.
  13. Kinetix 300 Hard Limits

    The Web interface should give you options of "Ignore", "Disable and Coast" or "Ramp and Disable".    I assume that "Alarm Only" means the same as "Ignore" since the drive isn't going to stop when it sees the overtravel signals.
  14. Fixed Cyclic Execution of Motion Tasks

    In general, the motion controllers and the motion subsystem of the Logix operating system take care of interrupts and motion planning by themselves.  As a programmer, I just try to keep my other program tasks from taking up too much processor bandwidth. I usually use a relatively fast cyclic task (5-10 ms) to hold my motion control routines, because I want to be able to react quickly to motion-related events, like the completion of a move or a change in gearing or dynamics.
  15. Fault 16# 0002 on 1756-DHRIO

    I'm a little confused by your description, so let's take a bit of a step back and review. Is the 1756-DHRIO in the same chassis with your ControlLogix CPU, or is it located in a chassis that is connected to the ControlLogix CPU via Ethernet and a 1756-EN2TR module ? You *can* put DHRIO and DNB modules in remote chassis.    The amount of data that gets moved across the network is substantial, but it works. The Unicast option won't be for the 1794-ASB entry in the I/O tree, but for the 1756-DHRIO entry itself.