Forum Replies Created
Do you mean “stacked” in the Cisco Stacked Switch configuration?
If you just need the switches to be on the same subnet, the you can connect them together with a CAT 5/6 and configure their IP addresses to be on the same subnet.
If you need to have different subnets on each switch (subnet A and subnet B) and a common subnet (subnet C) for the cameras, then you can use VLANs on the switches.September 14, 2020 at 3:55 pm in reply to: Warning: Duplicate Destructive Bit Reference Detected #19564
Good. Glad I could help.September 14, 2020 at 3:48 pm in reply to: Warning: Duplicate Destructive Bit Reference Detected #19562
I put it in my DropBox public folder. See if you can retrieve it from there.September 14, 2020 at 2:52 pm in reply to: Warning: Duplicate Destructive Bit Reference Detected #19557
Well the website won’t let me paste the file I’ve created into the website. Do you have some place I can drop the file and you can retrieve it? Right now it’s a .png (image) file but I can change it to a .pdf or other file format.September 14, 2020 at 2:27 pm in reply to: Warning: Duplicate Destructive Bit Reference Detected #19556
Give me a few minutes and I’ll draw up how I fixed it.September 14, 2020 at 2:20 pm in reply to: Warning: Duplicate Destructive Bit Reference Detected #19554
I’m not sure what happened to the attachments. If you can give me some context around what you were looking for, I might be able to recreate the attachments.
You’ve mentioned VPN restrictions a couple of time. Reading between the lines a bit here but let me see if I can summarize your situation.
- You have an entity outside your company’s IT security boundary that needs to have read-only access to your operation screens running on some type of HMI display. (You don’t say specifically what display your using for the operator screens but you did mention “PC” at one point.)
- Your IT security policy will not allow or support the use of a VPN to connect to the network the displays are on.
Does that sum it up correctly?
Is there any way users can have access to the operator screens either with or without FT ViewPoint without a vpn while they are outside the facility network?
I don’t know what your IT security policy is but, if it’s like most companies I have dealt with what you are asking for is usually strictly forbidden. First, most companies don’t expose the “Operational Technology” networks to the Internet because the security posture of the equipment on that network (PLCs, PACs, VFDs, I/O cards, etc.) is such that they are easy targets for bad guys. Second, VPN technologies are typically used to allow a known entity, whose end user device security is controlled by the company, to access internal networks. The VPN provides a tunnel through which devices can communicate securely. The VPN doesn’t control what the person on the other end can do once the connection is established. If the guy on the other end connects a machine that has a virus or other malware on it, that infection can jump to your internal network. It’s also possible that a bad actor could “hop” through the remote device and get into your internal network.
You mentioned that the external entity needs read-only access. Does that mean they need to be able to manipulate the screens or just watch someone else manipulate the screens? If the network where the screens are located can access the internet, you may be able to use a tool like TeamViewer. TeamViewer allows remote viewing of a PC or Mac screen.
Fred provided a link to a thread on using VNC. VNC wouldn’t work here with exposing the internal network or requiring a VPN. If, however, you had a PC that was dual homed (a network connection to your OT network and a network connection to a network with access to the internet), it may be possible to use a combination of VNC Viewer and TeamViewer running on that PC to accomplish what you want. The PC could use VNC Viewer to connect to the HMI display while using TeamViewer to share screen views with the remote entity.
My apologies for all the network speak.
I tried VNC but didn’t know I had to configure it on the PanelView. That’s probably why it failed to connect.
I’ll take a whack at it again with the VNC server enabled on the PanelView and report back here on the results.
Happy new year Fred.
I only have two Panel Views to deal with so I was looking for a quick and dirty solution (e.g., free) that would allow me to keep my lazy arse in the office and not have to walk out onto the production floor to update the network information on the things. (The original installers only put a bare minimum of network information on them.)
A PIDE’s output is an analog output that is used to drive a control valve or some other analog device by providing a 4-20mA signal. I’m not sure you will get it to drive what I am assuming is a solid state relay.
It never fails. Within a few hours of posting here, I figure out how to deal with the problem. I guess describing the issue so someone else can follow along clarifies things in my mind.
I ended up essentially what you suggested. I took the output of the GRT block and connected it to the ProgAutoReq input of the PIDE and to input of a Boolean NOT (BNOT) block. The output of the BNOT was connected to the ProgManualReq input on the PIDE. I confirmed that CVProg was still set to zero.
Now the operation is as follows:
When the tank volume is less than the set minimum, the output of the GRT is 0 (zero). The ProgAutoReq bit is set to 0 (zero), the ProgManualReq bit is set to 1 (one) and the CV is set to CVProg. Regardless of what the PV and SP are, the CV remains clamped at 0 (zero) and the valve stays shut.
When the tank volume rises above the set minimum, the output of the GRT is 1 (one). The ProgAutoReq bit is set to 1 (one) and the ProgManualReq bit is set to 0 (zero). The PIDE begins to control the valve (CV) based on the SP and PV.
From your spreadsheet it looks like you have addresses from both the .151 and .153 network Many-to-One NAT’d to the 10.136.0.36 address. I can’t really tell where your controllers are relative to the HMIs. Are the HMIs trying to communicate across the stratix to controllers on the other network?April 12, 2019 at 8:22 am in reply to: Limiting CV while maintaining controller in program mode #4000
This particular PIDE, under normal operating conditions, would not be set above 25%. But it’s good to know that if I ever need to change that, I’ll need to be aware of the condition you described above.
JimMarch 21, 2019 at 1:42 pm in reply to: Limiting CV while maintaining controller in program mode #3821
Turns out that I can get away with running the equipment in question while limiting the steam input to 25% all the time. I did this by setting the CV High limit to 25%.
I thought about doing something like what you suggested but I was holding out for a solution that wouldn’t require me to do any “switching.” I’ll implement this approach and see how it goes.
Just so I’m clear on the concept, you are running water through a heat exchanger into the tank. That water is being heated to a specific temperature using steam in the heat exchanger. The level of water in the tank is being monitored so as not to let the level get below the level of a steam sparger that is located in the tank. You are also using live steam to heat the water in the tank in order to maintain a specific pressure in the tank.
Does that cover it?
I’m having some trouble visualizing your set up. Would it be possible to provide a sketch of the physical set up showing the valves, etc.?
Would it not be possible to run the PID that controls the feed temperature valve in Override or Hand mode with a set CV, while monitoring the water temperature then switch back to Auto mode once you’ve achieved the water temperature you need for successful start up?
Thanks for the response. I actually stumbled across the help file about 10 minutes after I submitted my original post. Funny how it works that way.
JimNovember 16, 2018 at 11:08 am in reply to: FactoryTalk View Studio: Error Opening Project – Cannot Connect to Addin #3569
I didn’t think your Windows version would be the issue. I’ve had Studio 5000 on the laptop when it was Windows 10 Version 1703 and it’s made it through all the Windows 10 updates pretty much unscathed.
Post back and let us know how the WebRoot thing works out. I’m really curious about it given my past experiences with that software.