Micro850 + PanelView Plus via OPC

Hey guys,

I'm in a pretty weird situation and I'm looking for some input. Without going into too many details, I need an Allen-Bradley Micro850 to work with a PanelView Plus terminal. I know the two aren't designed to work together, but the choice of PLC is 100% out of my hands and the application requires a large HMI terminal with Class 1 Div 2 certification. The only PanelView Component terminal with that certification is too small (4 inches), so without changing the PLC the only real option I can think of is to interface the Micro850 with a PVP.

Even though the two devices can't talk natively, I was looking at this document and thought it was pretty interesting. From my understanding, it's possible to set up the Micro850 as a Modbus slave device on its RS-232 output, and connect that to the RS-232 connector on the PanelView Plus. Then I could configure KEPServer on the PanelView to pull data from the PLC via Modbus, and convert these packets to OPC tags which the PanelView can understand.

My main concern is that I have no experience with KEPServer, Factory Talk or PanelView Plus terminals, so I don't want to buy the terminal and software just to find out that this isn't feasible. If anyone with experience using these tools could comment it would be greatly appreciated.

I'm also confused about the different version of Factory Talk. From my understanding, I would only need Factory Talk View ME and FactoryTalk View Studio to design a PanelView application and have it work as I've described, with Factory Talk View SE more for monitoring. Any advice here would also be great.

This is a feasible application.

I have worked with these two products separately: PV+ to a Modbus Slave, and a different project with another HMI to a Micro 830 over Modbus RTU. They are definitely compatible.

FactoryTalk View SE is a client/server version of FactoryTalk View. If you aren't going to be building a server-based large-scale HMI system, you don't need FactoryTalk View SE's server or client software licenses.

FactoryTalk View ME is the single-screen version of FactoryTalk View. It's what runs inside the PanelView Plus terminals.

The FactoryTalk View Studio editor is where the two overlap. If you get the full-blown Studio license you can create both SE and ME applications.

What's far more common is to get the "FactoryTalk View Studio ME" edition, which is the editor for Machine Edition (PanelView Plus) applications only.

KepServer Enterprise is included with that software; you don't have to buy it separately. It's installed on the PV+ terminal as part of a firmware load process.

The Micro 850 current firmware can communicate over Ethernet with ControlLogix controllers, but the PanelView Plus Ethernet drivers (it's actually RSLinx Enterprise under the hood) have not caught up.

But you can use Modbus/TCP protocol (the Ethernet version of Modbus) instead of Modbus RTU over RS-232, to communicate between the PV+ and the Micro 850. It will be faster and just as simple.

There's a good RA Knowledgebase technote about this:

https://rockwellautomation.custhelp.com/app/answers/detail/a_id/520218/related/1

Thanks for the quick reply Ken. I've been trying to get a straight answer on this from Allen-Bradley all day and they weren't giving me anything concrete, so it's nice to see someone with some experience in this situation.

Your breakdown of the Factory Talk versions pretty much cleared up everything there. I have the trial version of KEPServerEX (not the same as Enterprise, but they seem relatively similar) from an older project I did, and I was just wondering if I had the basic idea for the configuration of the software. When I create a channel, the device driver would be Modbus Slave RTU Serial. Then I'd add a device with the Modbus model, and as long as all the addresses/baud rates/parities match up, everything would pretty much work out of the box if the registers are set up on the Micro850 and entered into KEPServer.

I'm not quite following on going the Modbus/TCP route. My understanding is that instead of configuring the RS-232 port to use Modbus RTU, it would use Modbus/TCP and the rest of the process would pretty much be the same. KEPServer would still take the data and create an OPC server, but instead of being sourced by a Modbus RTU slave it would be a Modbus/TCP slave.

Is the main advantage of this speed? I'm not really familiar with Modbus/TCP, so I'm not sure what advantages this would provide. Also, the Micro850 documentation (and that knowledgebase link) suggest that the embedded serial port supports Modbus/TCP, but within CCW I only see the choices of Modbus RTU, CIP Serial, ASCII and Shutdown for the driver. I'm not sure if you mean to say that it's possible to connect the PV+ to the Micro850 using Ethernet, or if maybe I'm using an older version of CCW or missing something.

Thanks again for the help

Modbus has three basic variants: Two serial, one Ethernet.

Modbus RTU and Modbus ASCII are the two serial variants. RTU is by far the most popular and common. They can run on many different serial links, but RS-232 and RS-485 are the most common ones.

Modbus RTU and Modbus ASCII adhere strictly to the Master/Slave principle; the Slave devices wait or a command from the Master. There can be only one Master, but up to 127 Slaves.

Modbus/TCP is the Ethernet version of Modbus. It's a peer-to-peer protocol, so devices are called "Clients" if they are asking for data, and "Servers" if they are replying with that data. There's no "Master" or "Slave" role.

KepServer Enterprise is almost identical to KepServer EX. The only differences that I know about are the supported protocol list, the activation mechanism, and the phone number you call for questions.

Since the Micro 850 has Ethernet and supports Modbus/TCP, and the PanelView Plus has Ethernet and supports Modbus/TCP, it makes sense to me that you can connect the two over Ethernet.

You can use RS-232 or Ethernet to connect these two devices. Either one will work.