pturmel

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About pturmel

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  1. You aren't wrong.  Siemens is number one in sales world-wide and number two in the U.S.  Rockwell is number one in the U.S. and number two worldwide.  Everything after that is very region dependent.  Learning Emerson (or others) is a good thing, but I wouldn't let my Rockwell skills suffer.  FWIW, supply chains have highlight some weaknesses in Rockwell--I've had some clients expanding their 2nd tier platforms.  Omron's NJ/NX newer stuff and Keyence KV-7500 and KV-8k families, in particular.
  2. If you can.  Distance or other electrical considerations might make it unworkable.  That's why manufacturers sell isolated cards.
  3. Control Melsec-FX-5U over internet in realtime

    Start a new topic in the appropriate category.  I'll be happy to offer my 2¢.
  4. Control Melsec-FX-5U over internet in realtime

    If you have a commercial interest in LECPServer, you should disclose that when pitching it.  General sales pitches for LECPServer belongs in the For Sale, Employment, Services, or Wanted forum topic.
  5. Control Melsec-FX-5U over internet in realtime

    Simply not true.  OPC/UA supports high-quality encryption and authentication, and its report-by-exception architecture is bandwidth efficient. Some OPC server implementations may skimp on these features, but the ones from major brands certainly have them, including Kepware. The only real weakness in the OPC/UA model for internet use is the need for subscribers to be able to route to servers to make the connections.  NAT-friendly reverse connections are not in the OPC/UA specification.  But then, all of the base protocols for PLC suffer from this, and it appears that LECPServer doesn't solve it, either.  MQTT and similar brokered protocols exist for this reason. Or that problem can be solved with VPN techologies, for all of the above.
  6. help with first time program

    If you are comfortable with logic with real relays, then you should adapt to PLC ladder logic easily.  The digital I/O part of a PLC platform can be considered a black box with a nearly unlimited supply of tiny interposing relays, each with a nearly unlimited supply of tiny contacts of many kinds.  PLC input cards feed dedicated virtual interposing relays with contact that you use anywhere in your logic.  You create and use other virtual relays in your code, including options for latch/unlatch coil pairs.  PLC output cards are similar to these virtual relays, but include a physical electronic or mechanical contact to drive real-world loads. PLC's also provide virtual relays that mimic real-world timing relays, mechanical counter mechanisms, et cetera. The techniques common for real relay logic, like seal-in branches, are commonly used in PLCs, too.  Just with virtual contacts instead of real ones. One application note:  stop buttons and similar devices that need to fail in the "off" position are usually wired to a real-world normally closed contact, and then used with opposite virtual contacts in the PLC. On the analog side, PLC platforms emulate many different kinds of analog switches, with nearly any kind of math functions you like. So, the relay part of your real boiler control should look very similar when translated into PLC ladder logic.
  7. That's nice, but it seems to be opposite direction of the OP's question.
  8. CC-Link IE Protocols

    Interesting link.  As a collection of best practices and techniques for determinism, TSN is great.  As an implied sole solution for determinism, the way it is marketed and twisted into some commercial products, not so great.  Especially as a newcomer whose core is technology has been standard in Rockwell products for many years.  Like, more than a decade.
  9. You can't edit them online, but you can create new ones online, and online delete unused UDTs.  You can create new tags with new types online, and online delete unused tags.  So if you absolutely must, you can online edit your way into new UDTs.  (For part of that time, with two complete sets of tags of those types.  Dragging and dropping from a temporary offline copy of the program, open in another instance of Studio 5000, is a big help.)
  10. This. Logix UDTs are Rockwell's implementation of structs.  There are some quirks, like its odd  and non-optional 32-bit alignment (64-bit in some case with v27+ firmware) rules.  (In summary:  single 8-bit types are byte-aligned, single 16-bit types are 16-bit aligned, all else is 32-bit aligned, including all all arrays and nested structures.)
  11. CC-Link IE Protocols

    PTP packets can be priority-marked, too.  And PTP-compliant switches measure and report latency across the switch itself to maintain accuracy.  TSN incompatibilities are simply attempts repurpose existing technologies with vendor lock-in.  I'm less than impressed.  (Not that it doesn't work, but that there's a bunch of hype.) Logix processors provide detailed information about their active grandmaster clock (via GSV), so the alarming is possible and configurable.
  12. Yes, you must tie the commons together when using that card.  It is not isolated.  If you need isolation, you must use the 1756-IF8I.
  13. CC-Link IE Protocols

    Rockwell has been using the same time synchronization technology as TSN for many years--IEEE 1588, also known as Precision Time Protocol.  It is a fundamental part of CIP Sync, the TSN-ish extension to EtherNet/IP and related technologies.  So, no, CC-Link is not first in this space.  They are just using the fancier new buzzword.
  14. Yeah, that calls for a SCADA system and database to feed the PLC.  The SCADA would load several centimeters of data into a ring buffer in the PLC, then dynamically load more from the database as the servo advances. This is exceedingly non-trivial.
  15. Siemens

    Mwah, ha, ha, ha! Compare the native languages of the people who designed them.