pturmel

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Posts posted by pturmel

  1. Posted

    There were some buggy loopholes in older software, but in general, you can add Rockwell products to a local ControlLogix chassis, or remote ControlLogix chassis that is already in the I/O Tree.  You can add non-chassis generic ethernet devices.  I suspect you can also add products that provide a Rockwell-compatible Add-on Profile.

    I'm not sure about adding a completely new chassis.  I'll try this in my lab later today.

    Some devices that can be added on the run can be deleted on the run, too, as long as all of the code references to the corresponding I/O Tags are gone.

  2. Posted

    3 hours ago, xunilbama said:

    StarTech RS232 to Ethernet Extender

    You are misquoting the product.  It isn't ethernet, just happens to be the same kind of cable.  Ethernet cannot go 1000m either.  It is likely doing some form of RS232 to RS422 transformation (but possibly muxing more than one status signal on certain pairs).  The key to success will be figuring out how the pairs cross between the two units.

  3. Posted

    4 hours ago, aleksander said:

    where I can find declaration of supported range of RPI?

    In the [Connection Manager] section in the ConnectionN = ....  where the comments show O=>T RPI and T=>O RPI.  Unfortunately, those fields are blank in the linked EDS, so you'd have to find the acceptable range elsewhere in Cognex's documentation.  Normally you'd find a "ParamN" shown there, and you'd look that up in the parameters section to find the min and max allowed (and preferred default, usually).

  4. Posted

    3 hours ago, Dinos said:

    using H1 

    No idea.  Not familiar with the CJ family of processors.  Only lightly exposed to the NJ family (with Sysmac Studio).  I used AB pseudocode for a CPT instruction. You'll have to translate that to the appropriate bit-wise logical operations in CX-programmer.

  5. Posted

    I'm not familiar with those instructions, but there's math that can perform the same task when searching from low bit to high bit: 

    Output = Input AND ((NOT Input)+1)

    That takes and input word with any bits turned on, and yields an output word containing just the lowest 1-bit.

    (I'm not aware of any math trick that yields the highest 1-bit instead of the lowest.)

  7. Posted

    It's been nearly 30 years, but I remember the Moore 352 having different SKUs with varying capability.  { Ah, there's a table in the manual Hati provided. }  If you don't have the specific SKU, you won't have some of the function blocks.

  9. Posted

    1 hour ago, Goran Vuckovic said:

    It look like you have not used it.

    Correct.  You may be right about everything else it offers.  But it definitely has a lame Modbus implementation.  If the only practical common protocol between the PLC and the drive is Modbus, then I consider this drive absolutely unacceptable.

  10. Posted

    Wow!  I perused the inverter manual and the network manual and have decided that the FR-A800 has the lamest Modbus command and status interface I've ever seen--particularly the use of specific modbus registers with different meanings for read and write.  There's no way to find out the last instruction sent to such a register.  The parameters for control source selection are also almost unbearably complex (in the manual, §5-9-1 through §5-9-3).

    There's no way I'd ever recommend this drive to any of my clients. :-(

    1 person likes this

  11. Posted

    What made you think Sysmac studio supports VB?  The screen shots suggest you are trying to place VB into a Structured Text PLC program.  In a PLC program, you have to use structured text syntax, not VB syntax, and call the platform's SD memory card instructions.  You should get the manuals W501 and W502 from Omron.

    Ah, NA HMI, not a PLC.  I'm not sure what it supports, but looks like it is very different from Siemens.

  18. Posted

    2 hours ago, MechEngi said:

    The end router will eventually receive the packet and somehow (this is the part I'm interested in, if there's a setup to do) send it back to the right place ?

    Unlikely, highly dependent on the router implementation.  Lots of simple ones will choke on sending a routed packet back out the same port it came in on.  Even the best routers will choke if a given subnet reaches the router via multiple paths.

    Mixing subnets on one switch is simply unsupportable (unless you are segregating by VLAN, and the router knows the VLANs).

    Supported layout, if you are not using VLANs:

    • Every switch must have one and only one subnet assigned.
    • Routers must have single (logical) ports connecting to each subnet.

    If you are using VLANs, each VLAN can be considered a separate switch, even across multiple physical switches, and then the above rules apply to the VLANs themselves.

    (An IT person who set up what you described is incompetent.  IMNSHO.)

  19. Posted

    37 minutes ago, Hobbes said:

    ProSoft unit can struggle with the quantity of data between SCADA and the SLC on DH+

    Huh.  I'm not so sure this isn't just someone's disappointment with the DH+ data rates, which, even at its fastest, is multiple orders of magnitude slower than ethernet.  The CLX/DHRIO combination won't go any faster, I would think.  (My experiences with Prosoft devices are entirely positive, fwiw.)

  20. Posted

    1 hour ago, MechEngi said:

    these two devices are interchangeable

    Nope.  Let me summarize:

    • An ethernet hub broadcasts packets coming in one port out the other ports.  This behavior matches the original coaxial taps and can be implemented with just switched amplifiers.
    • An ethernet switch examines the MAC address on packets entering a particularly port and attempts to direct the packet out the port that is known to have that MAC address, eliminating excess traffic on other ports.  Where not contended, modern ethernet switches will stream the packet from inbound to outbound ports with just the latency of the header.  Switches fall back to broadcast for unknown MAC addresses, and apply various rules to deliberate broadcasts, multicast, and certain other kinds of packets.
    • An internet protocol router examines the destination IP address of a packet entering one port (and if ethernet, addressed to the router by MAC) to determine which of its ports, if any, have a compatible subnet.  If configured to do so, the router will forward unmatched packets to an upstream router.

    When you have two incompatible subnets living on the same switch, packets destined for the opposite subnet will be directed to the source's gateway MAC address for routing, since the subnet indicates that the packet is not local.  If there's no router to echo the packet back out onto the switch with the corresponding MAC target (learned with ARP), the packet will simply land in the bit bucket on the floor.

  22. Posted

    I'd lean towards option 2, with a new panel for just that processor, and no I/O there.  With a UPS for the controller and a new ethernet switch just for the PLCs in the room.  Then remote I/O to replace each micro.  The remote I/O doesn't have to AB, either.  Anything with EtherNet/IP support will run great, and might have better supply chain options.

  24. Posted

    If your measurement method is slow or imprecise, fundamentally, the only solution is to alter your measurement method.  If you have a high speed clock available, a common technique is to count clock pulses from sensor leading edge to leading edge, giving you the signal period.  From which you can take the reciprocal to get frequency.  If the available clock rate isn't high enough for the desired precision in one period, count it for multiple periods.

    Using a PID controller or not has no bearing on the measurement of your process.