EtherNet

Hey Guys,

we are using Ethernet for all machines communication, so i'm wondering as an electrician what i have to know about ethernet.

thanking you in advance for your help.

Jeff

Ethernet????? PASS!!!!!

Get yourself a Fluke NetTool handheld meter. It can be connected between the machine and network. It will show IP addresses on the network, protocols being used, and also do cable checks.

Also look at a piece of software called netdecoder.

http://www.fte.com/net01.asp

You will need tools to see what the network is doing. You can probably get by with reading the ethernet manuals from the hardware components.

As an electrician:
1. Have to know what type of cable and connector to use for Ethernet.
2. Have to understand the wiring classification.
3. Have to know the best practices and best way to run the Ethernet cable (no shortcut).

Want to become a network communication specialist:
1. Understand, and get use with Windows and related application software for Windows.
2. Understand the Ethernet TCP/IP technology.
3. Understand and setup the Ethernet network.
4. Understand bridge, hub, switch, bandwith.
5. Understand and setup the security.
6. Understand the differences between internet, intranet, extranet, VPN, LAN, WAN...

Want to become an industrial network specialist for industrial high tech products:
1. All of the above.
2. Understand, install, setup and program the PLCs.
3, Understand, install, setup and program the intelligent industrial control products such as Drives, smart relays, smart sensors, etc...
3. Fully understand the application.

That's my 2 cents comments. Hope that helps!

KN

first of all thank you, i know how to program, configure Ethernet card, control net and device net, Synk Link and use them in a PLC program, how to talk with 2 PLC's or more using consume and produce tags, or user define data table, but what i do not really understand the IT side, i mean sub net mask and all the clasaes A, B, C and D, router, Hub, how to set your Machine as main server and get another PC as a back up.
thx again.

Hi Guys,
As i mentioned before wa have applications using Allen-Bradley Control Logix PLC's all talking ethernet (plus the HMI's), now we are looking to pull some data and trend them for production wise etc., i could pull some data using DDE /OPC server but our guys wants to trend these data, another thing is is i use the DDE/opc server to pull data into excel, by doing this do you think guys I'll affect the ethernet trafic?, i know there is a system, which call PI system to do such a thing , but it s very expensive and you pay by tag,so any help from you guys,

thx
Jeff

Hi,
A course in subnetting and routing algorithms would take a bit more than a response here, but I used a book at Uni called "Computer Networks" by A. S. Tanenbaum, Prentice Hall, ISBN 0-13-394248-1 This book cover both ethernet and communication in general.

Regards,
Fredrik

Hi Guys,
As i mentioned before wa have applications using Allen-Bradley Control Logix PLC's all talking ethernet (plus the HMI's), now we are looking to pull some data and trend them for production wise etc., i could pull some data using DDE /OPC server but our guys wants to trend these data, another thing is is i use the DDE/opc server to pull data into excel, by doing this do you think guys I'll affect the ethernet trafic?, i know there is a system, which call PI system to do such a thing , but it s very expensive and you pay by tag,so any help from you guys,

thx
Jeff

Have a look at the 56SAM Historian. See http://www.oldi.com/sam_home.htm

Ray W. Valentine
Sales Engineer
Online Development Inc.
Ph.: 865-251-5222
Email: [email protected]

To all,
With OSI Pi you will pay on a per tag basis, same with Canary Labs. This is true of most trending packages.

You will require RSLinx to be installed on your data collection machine.
This will be the DDE \OPC server and connect to the CLX processors. In the data collection configuration you specify processor, tag, interval
and delta. Delta is useful in reducing the size of the data collected, no delta, all data is logged. If a small delta is used, the value must
exceed the +/- delta limits and only then the new data is added to the data collection set.

Traffic is a concern. Do moves or copies in the CLX to get all data into blocks that the data logger will read. RSLinx will optimize the read
blocks and do it as efficiently as possible. Set the interval to something realistic, 50 milliseconds is not, 1 second is OK.

DDE was the precursor to OPC. If at all possible, avoid DDE. OPC is faster and has some diagnostics built in. See http://www.OPCfoundation.org for
more info. Excel was only a DDE client in 97, not sure of current state now.

We use Canary Labs for maintenance trending, 1 second and we control the additions of tags (need a tag added? done in 1 minute) and Pi for long
term trending. In our organization structure, since Pi is controlled by others, it can take over a week for a tag to be added.

Hope this helps

Rob Barrese
Dofasco

Get Microsoft's "Network Essentials" it is a fairly easy read, I think available from what used to be Microsoft press, possibly Amazon. It is
very good at explaining in laymen's terms the basics. Also has fairly good lessons on CD, last I got was 2nd edition but long ago.

On another front and my 2 cents worth...................We are all having to do 10 peoples jobs now, Engineering, IT Expert, Technician, Electrician Draftsman, Finance, Accounting, Business, Secretarial, and then when I go home Financial advisor (retirement), Medical Specialist and Billing Specialist (my new medical plans)and on and on. It didn't used to be like this.............

Just like I tell Electricians that Process Control is a whole other field and Process Control people that the IT world is a whole other
career, the new modern world wants "General Practitioners" instead of "Heart Surgeons"..............which is great unless you need heart surgery. Unfortunately I get nervous when my "Instrument Man" is working on 13800 Volts after doing Instrumentation for 18 years, or Engineering is setting up the network security all because corporations merge jobs to save money.............But then again when I need heart surgery (heaven forbid) I want a specialist who knows what he is doing in detail.

Dave

Re. Status of Excel as a DDE/OPC Client

Excel is still only a DDE client, and not ordinarily an OPC client so it is still subject to all the usual problems with DDE. Suffice to say that it is very very messy.

When I say "Excel is not ordinarily an OPC client", I mean you can make Excel into an OPC client using an Addin.

For an OPC add-in to make Excel function like an OPC client see:
http://www.opcware.com/opc_excel.html

These add-ins will work for the real-time opc servers like RSLinx (through OPC DA interface), and it will also work for the historical databases like PI and Canary (through OPC HDA interface).

No DDE involved, user-friendly user interface etc etc.