AB device net

[Alan Case]

RS485 is the physical connection ie the cable. DH485 is the protocol, it is a proprietary AB protocol and as such is not compatible with other companies 232 to 485 converters.

Ken gave 3 really good methods to solve your problem.

Re-read his post and answer the question of how fast do you want your data and how much data do you want to send.

This will tell you what method to use. Once you decide on the method then if you are still having problems come back here with the method you decided on and I will try and help you.

You can get cards for the SLC that have DH485 ports, I was going to give you the model number but see my other post for the reason.
I dont think multiple DH485s this way are the go. Kens methods are more appropriate. Regards Alan Case

 

[Beryl]

Ken, Don't the new SDN's have 394 words available? Or do I not understand the difference setup and available. (probably) I know you have to change the settings on the new revs from 361 to 395. Not that it makes much difference here. He would still need two cards depending on how much info was wanted.

Thanks,

 

[micah1234]

OK I re-read Kens notes. Let me make sure eveyone knows what I need. What I have is 68 micrologix 1000's that operate 68 machines. 6 of them were originally put on a DH485 with a SLC-503 and a Panelview 550. The 550 currently allows setup of these machines and reading of setup and cycles per shift. I need to still be able to use the 550 on the plant floor (hopefully to set up all 68 machines). As far as stored data, it can be uploaded from the micrologix once in awaile, no rush. But I will still need to be able to change setpoints in the micros thur the 550. And when all this is working, I will need to be able to connect a computer with RSViews to allow management to "look" at the process, and maybe be expandable to other areas of the plant. Now, one more thing, what about the idea I had for having several DH-485 networks and allowing the SLC-503 decide which one to look at. The micros would have duplicate addreses but the SLC would know which group it was looking at and therefore which data file to move data into and out of. Can you switch networks like this, or will it cause some kind of faults?. If I could, I could bring in other DH-485 networks thru switching and upload data from them. By the way I can't spend $38,800.00 for ethernet converters alone and still afford the rest of the equipment and software. I tryed to tell them "you can't get there from here", but the reply I got was "well then what do we need you for". I hope he was joking.. mg

 

[rsdoran]

My first thought is that what you want to is going to cost..one way or another. 3 days or 3 weeks this is not nor can be an overnight endeavor.

Just to throw more ideas out there I will ofer one. It seems that DH485 etc break down after so many nodes and the components are expensive.

What about building say 5 computers, no monitors needed except for setup/troubleshooting, with a KTX card and ethernet. A basic PC with mobo, ram, net card and hdd can be built for $150, add a KTX card for $200, plus windows. Lets say $3000 for the lot, probably less because you will not need the latest and greatest.

Now comes the part there are multiple options for. The computers can use DH485 to communicate with 10-15 plcs and ethernet to pass the data onto management.

May want to change your mind about monitors and use this option instead of or in conjunction with the panelview, maybe multi-license the RSView or some other HMI package.

Seems this would allow you to buy all the software/hmi/scada needed and viable hardware to manipulate the data.

Just throwing out ideas

 

[Alan Case]

Hi, RSView or the panelview does not need to access the 68 micrologix's.
Consolidate all the data in the SLC both for status and command. You can connect a point to point panelview to view and modify this data. You can even modify your existing DH485 panelview to a DF1 panelview if you have the firmware to flash it. The 485/serial card I was thinking of was a 1747-KE or 1746-KE. Regards Alan Case

 

[Platootod]

Some tutor

There is some tutor from www.koldwater.com
about devicenet you can download and try
3 times or 3 days ...
May be can help you in some information that you need

Platootod
Mechatronics RIT.Nonthaburi Campus

 

[micah123]

I figure I can spend $20k, I already have a few of the AIC modules I have the DH-485 Panelview and PV software. I already have the SLC-503 in place. You guys have given me a lot of food for thought. I will need to finilaize the proposal in a couple of days. If I use several cards in the SLC chassis with DH-485 ports, will they be differently addressed in the SLC. It appears that some of the ones I looked at allow use of the on card DH-485 port or the one in the processor, as if I still only had one usable port? By the way, thanks for all the ideas and help. mg

 

[Ken Roach]

The way I would do this is to configure the SLC-5/03 Channel 0 serial port as DF1 Half-Duplex Master and all the MicroLogix 1000 as Half-Duplex slaves. Each MicroLogix would be equipped with a 1761-NET-AIC.

The DF1 Half-Duplex protocol allows 255 nodes, so you could make everything one logical network. RS-485 wiring, however, only supports 31 nodes per segment so you will have to link the segments together.

You can link RS-485 segments together with the 1761-NET-AIC by connecting Port 2 to Port 2 with a 1761-CBL-AM00 cable. With DH-485 protocol you can only connect two segments, but DF1 Half Duplex is much more forgiving on timing and I think you could connect several more without difficulty.

If you use the 1761-CBL-AM00 cable to connect the MicroLogix 1000 to the 1761-NET-AIC, you do not need a 24VDC power supply for the Net-AIC (if that's not available in the cabinet, it might be a factor).

You would perform MSG instructions to the relevant MicroLogix slave when the PanelView operator chose which wheel press to monitor and set up. The SLC-5/03 Channel 0 DF1 Master port can be set up in "MSG Based" mode so that there's no extraneous polling traffic.

The big gotcha in this idea is that the MicroLogix 1000 units need to be at least Series D to include the DF1 Half-Duplex protocol. You're simply going to have to check.

If the MicroLogix don't support DF1 Half Duplex, then we're going to look at multiple DH485 networks with multiple 1747-KE modules and a baffling "remote link" addressing scheme.

 

[Ken Roach]

I'm not 100% sure that you can "gang together" more than two networks. You might want to get in touch with your local Rockwell Automation office and see if they can give you some ideas about linking more than two RS-485 DF1 Half Duplex networks.