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  1.   In a certain area of our facility we have several machine that manufacture a handful of products. These machines were built at random intervals starting in the late 80's and consequently have a range of different PLCs that are used to control them (SLC 500 to ControlLogix L61).   The other areas of our facility use a server that has a historian installed (Canary) and the client (Axiom) is installed on our computer so we can view data trends in real time.    I would like to network our PLCs mentioned in the first paragraph to this historian to gather production and maintenance data.   I know that I need to network these devices through an OPC server (which we have).   Several of these devices have been connected through DH+ and/or Ethernet networks in the past but are no longer connected.   We recently connected some of the DH+ Devices to the Ethernet network (just to see if we could) with a Prosoft AN-X2-AB-DHRIO.   My questions are:   Are there any best practices for networking devices with different protocols, i.e. DH+, Ethernet, etc.? Is the way we have it set up now (with the Prosoft DH+ to Ethernet bridge) a robust (scalable, etc.) solution? Is there a better way to do this? Is it worth getting EtherNet/IP cards for the PLCs that don't have them?   If anyone has any experience with a similar scenario, insights/advice would be much appreciated
  2. Hi All, Networking guy here, looking for network experts on a AB PLC (1756-EN3TR/B v217021900) which seems to STOP ARPing for a device after 10 ARP's. The device is purposefully powered down, but when powered up, it can take minutes before the PLC sees it again. The PLC team says only changes in the PLC's logic are made. When an older backup is restored though, I do NOT see the issue somehow. 1) The devices that are powered down are back on the network and reachable within 10 seconds or so (ping). The initial thought was that they were not even on the network, but they are. Just that PLC shows a comms loss. 2) With the 'good code', the PLC, once the device is offine, keeps sending ARPs to find the device. The first one is a directed one, the subsequent ones are broadcasts. These broadcasts keep happening till the device is back online and is able to talk to the PLC again. 1st ARP after comms is lost: 474.423859     Rockwell_cf:a7:6c     Hilscher_2e:ea:08     ARP      60     Who has 192.17.150.208? Tell 192.17.150.30 Next and subsequent ARPs after the first one: 475.423471     Rockwell_cf:a7:6c     Broadcast             ARP      60     Who has 192.17.150.208? Tell 192.17.150.30 These ARPs keep happening every 1 second, till the device is online again. 3) With the bad code, the PLC, once the device is offline, sends only 10 ARP messages total and then stops sending ARPs altogethe . Then it takes 10 minutes* before it sends another one. If the device is backup online by that time, the PLC finds it right away. SO with these 2 different code bases, how is that a low level L2 protocol like ARP is impacted so much. The PLC team tells me that they have no idea and not set anything related to it. My question is where is the ARP network behaviour governed and how to change it? How can older code which supposedly only has changes in logic have different ARP behavior? * The 10 minutes interval might lead people to think it's a ARP timer and most likely it is, but then people usually ask about gratuious ARPS (garp) and I've verified that they make it through from the device to the PLC OK. If the device is offline for say a minute, the PLC mirrored port does indeed see the garps, yet at that point the PLC is no longer ARPing and regardless of that garp, it has to sit out the time till it sends a next ARP till it connects. Thus, I suspect the coming back to life process is governed by the PLC ARPing for it, and not by the detection of a garps. Thanks everyone!  
  3. Hello,             I need to communicate Power meters ( GE Multilin EPM 5500P) to  GE Multilin EnerVista Software. The present communication system uses Ethernet for communication from LAN Switch to Computer. There are a few existing Power Meters which need to be connected to the  Network. The Meters having output ports as RS485. I need to use a convertor for that right. So when I contacted GE they told me to use GE Multilinet Serial to Ethernet Convertor. But due to the price and unavailability of the material I am thinking to use a universal convertor. Is that compatible for Multilin Devices?? and In Case of using a universal Convertor does we need any other drivers for that. Please Help Me.. Thanks In Advance  mnetman-a3.pdf multinet (1).pdf PM-GE.pdf
  4. I an seeking guidance on how to link two mitsubishi PLC over Ethernet and have them pass bits/words between them.  PLC 1, Q03UDV built in port  ---- GXWorks 2 v1.54N   192.168.1.39  (QJ71 in slot 1 is also available if req'd) PLC2, Q02H with a QJ71 Ethernet card in slot 2.  Same GXworks2   192.168.1.35   I know with a modbus or CCLink setup, there is a place to declare the buffer > X/Y parameters, but i have found no such parameters for the ethernet connections. I found 1 document describing the JP.Send instructions but I have not been able to get that to work from the example.    any help would be greatly appreciated.     
  5. [Hello, this is my first post - hope I posted in the right place.] We have multiple Logix5000 PLCs and are using Wonderware 9.x HMI. There are 4 SCADA PCs running Wonderware. Each is set up with DAServer and they pull the tags directly from the PLCs. On one SCADA PC, DAServer is continuously throwing the following error when attempting to read tags from a specific PLC: "Encountered following errors while establishing connection for New_PORT_CIP_000.HSPS.Backplane... ExtSTS=011A: Target Application cannot support any more connections". The tags from that PLC don't get updated on this particular SCADA PC. The "HSPS" PLC reports 7 active connections, with 64 available. CPU utilization is ~30%. The other PCs are not reporting this error and are working fine. I would be very grateful for any suggestions to track down this error. Thanks!
  6. Hi, I work as an industrial programmer primarily dealing with Allen Bradley, Mitsubishi, and Omron PLC's as well as various peripheral devices. I would like to begin the process of learning computer programming as it pertains to the manufacturing industry. I'd like to learn how to write databases (SQL, etc) and VB apps and eventually I'd like to be able to write applications that can communicate with PLC's and other devices (although the last one would be a ways down the road).  I have very little experience with computer programming so I don't really know where to start. What language should I learn first? What free software is available to learn with? What resources do you recommend I use? I've downloaded Visual Basic Express and found some introductory courses online that I've just started but if there is something else I should've started with I'm open to suggestions. Thanks
  7. I would like to bring up a topic that I've been been bouncing around in my head for the past few months. I make a living as an industrial programmer, sequencing using PLCs, dealing with drives, networking, controlling heavy machinery. All the hardware we use are from established companies like Allen Bradly, Sick, Cognex, Delta, ABB, etc... big $$$, you pay for the software, pay for the hardware and pay for the support. It's not uncommon for a large control system to cost $50k+ (hardware only) By night I'm just your regular maker. Programming AVR series uC, ARM series, playing with various open source hardware Arduino, RPI, Teensy, 3D printers, designing PCBs, stepper motors... whatever I can get my hands on. Both worlds are the same... but completely different, and there is ZERO overlap. I'm interested in why other people think this is, I'm sure that makers don't get into the industrial stuff because the price point. I'm not going to pay 8k for a AB Logix rack... are you kidding me? but vice versa? is the lack of support really all that daunting? I find OS stuff to be way more powerful, understanding something from the bare metal is the most amazing feeling, and being able to modify it to your needs is even better. Digging into somethings source is without an argument the most flexible platform to build on, and knowing the board level schematic for a chuck of hardware opens up a world of opportunities... Then lies the ethical dilemma... If I was to profit off other people's work, does this make me a bad person? What if I push the changes back into the development (which frankly I have no problem doing) I would love to head other people's opinions...
  8. Submitting with an SLC

    Hello, At the plant I work at there are devices with IP addresses starting with 192.168.0, 192,168.1, and 193.168.2 The SLC in question is on 192.168.2 We would like to access it from our laptops which are on 192.168.0 The laptops have their subnet mask set to 255.255.252.0 and we are able to pull see other controllers on the 192.168.2 network. However, for some reason we can't with this one, not even when I'm plugged directly into the Ethernet port on the controller unless we change our IP address to one on 192.168.2 I believe the subnet mask on the controller isn't set right. Can anyone tell what I'm missing here? Here's an overview of the current settings: Laptop: 192.168.0.20, 255.255.252.0 Controller: 192.168.2.17, 255.255.252.0 Any help would be greatly appreciated. Ben