HMI to dynamically IP on PLC

[fostergr1]

I have a FactoryTalk ME application I'm trying to get working to interface a PanelView Plus with a Micrologix 1100. It is used for demonstration purposes and will be moved from one network to another frequently. I'm curious as to whether or not the HMI can be setup to locate the PLC by a DNS name as opposed to having the device path/IP hardcoded in the HMI application. I would prefer to use DHCP addresses on both the HMI and PLC and not just the PLC. But within FactoryTalk, in order to setup communications, it looks like the HMI must have a device path assigned for the PLC that includes the IP address. So once I move it to another network, that IP would no longer operate with other machines on that new subnet. This demo unit will possibly be moved around between 5-6 different subnets.

Is what I'm trying to do even possible?
Thanks.

 

[Ken Roach]

Welcome to the Forum !

Unfortunately I don't think this is possible.

While a MicroLogix or any other RA controller can have a Host Name when it gets an address via DHCP, RSLinx Enterprise (the communication drivers inside FactoryTalk View and the PV+) don't support resolving IP addresses using host names.

The older PC-only RSLinx Classic supported Hostnames in the Host List, but most people just put in IPv4 addresses.

But I have never seen Host Names mentioned or used with RSLinx Enterprise.

 

[nwboson]

You could consider putting a small router on your demo hardware. You would hardwire the IP addresses of the PLC and HMI on their own PLC network: then port forward using the router from the foreign network into your PLC network. At least then the only change would be to the router port forwarding addresses whenever you moved to a new network. Or you could put the PLC and HMI on the router's DMZ to be able to forward everything: once again, you would only need to make a small change to the router as you moved from network to network (this is assuming you want to expose the HMI and PLC on the foreign network - if not, there would be no changes necessary as you moved across networks).

 

[fostergr1]

Thanks for the welcome.

I thought about the router initially. But, we are trying to keep the expense and the bulk of this solution down. But if I really have no other options, I'll just have to deal with it. I'm really not using these devices the way mother nature intended.

I appreciate your assistance, both of you. And thanks for not calling out a newbie.

Oh, ever heard of a small DIN rail-mounted router you might suggest?

 

[nwboson]

For a demo, I'd use a Mikrotik RB450G, a case for the RB450G (I buy them from flytec), and Din rail mount it with a Digikey 277-2289-NO dinrail adapter. It will run from your 24VDC. You'll have about $120 into the whole thing - and you'll have a 5 port gigabit router with every feature you could ever imagine. And the RB450G is rugged - typically used in outdoor stations in terrible weather conditions, so a good fit for industrial IMHO.

It can be a little challenging to configure a Mikrotik router but when I use their web-based configuration software, I seem to always figure out how to get it to do what I need.

There are huge differences from one router to the next but since it sounds like all you need is port forwarding and/or a DMZ, most any router should be able to do that. I use the Mikrotik because they simply have a thoroughly comprehensive feature set - which can make them more of a challenge to configure, but I prefer knowing I can run redundant wiring, or setup a VLAN, or a VPN, or have a separate network on every port, and on and on.