Introduction to Networking Interact

burpfancyElectronics - Devices

Nov 8, 2013 (4 years and 8 months ago)


Net/DDE Introduction to Networking

CTC Parker Automation




Introduction to Networking

Net/DDE Networking Interact and DDE

CTC Parker Automation



Lesson Objectives

After completing this Lesson, you will be able to:

Configure a basic network

Optimize a network system for optimal performance

Educate others on what makes up a

Net/DDE Introduction to Networking

CTC Parker Automation




Networking Concepts

This section provides an overview of basic concepts and features of Networking. The
following section discuses general networking.

What is a Local Area Network?

There are five basic parts to a LAN (local area network).






Adapter Cards


Network Software


Application Software using network protocols (NETBIOS)

A LAN is a local area network. A LAN enables you to connect a group of personal
computers together. During this overview we will get acquainted with works
tations file
servers, LAN cables, and network adapters such as LANtastic, ARCnet, EtherNet, and
Token Ring cards. After we discover what makes up the hardware side of LAN's, we will
move into the software components of the LAN systems. We will learn abou
t network
operating systems such as Novell's
NetWare, OS/2 LAN Server, LAN Manager,
LANtastic, NetWare Lite, and Windows for Workgroups.

WHAT CAN A LAN (local area network) DO?

A LAN can do virtually everything a mainframe computer or minicomputer can d
o at a
much lower costs. Here are seven basics for a LAN system. These are things a network
system can do that a local stand alone system cannot.

Share files
: A LAN enables many users to share a single copy of a file stored on a
central file server co

Transfer files
: A LAN enables you to copy files from machine to machine without
having to exchange floppy diskettes.

Access information and files
: A LAN enables anyone to run the Interact software or
any other application software for that ma
ter, from any of the workstations.

Share applications
: A LAN enables two people to use the same application program.
Several people could view the same Interact program.

Simultaneously key data into an application
: A LAN aware application like Inter
enables several people to Key into the program at once. However, Interact's security key
must be on each machine before it will run the program, even if you have a workstation
server relationship.

Printer Sharing
: Share printers for Alarm logging,

Historical Trending, and

Peer to Peer communications
: Interact uses the ASCII INPUT MESSAGE TOOL to
send messages from one station to the next.

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On a LAN, each personal computer is called a

except for one or more
ters designated as
file servers.

Each workstation and file server contains a
network adapter card. LAN cables connect all the workstations and file servers. In
addition to DOS, each workstation runs network software that enables it to communicate
with t
he file servers. File Servers, on the other hand, run network software that
communicates with the workstations and other file servers. File servers many times may
only be running network software. A computer system may be both a file server and
ion all at once. This type of system is known as a
peer to peer
network system.

The workstation is usually manned by people, file servers are
located in a separate room or control office. The workstation works only for the person
sitting i
n front of it, while a file server enables many people to share its resources.

In contrast to the workstation, a file server is a computer that serves
all the workstations. Its primary functions are storing and retrieving data from files
ared on its disk. For example, a customer may by Interact PowerStations to run down
on the floor. These machines collect the alarming and historical data and send it to a
server in the control room. This machine takes that data and displays it using the

HTM or
AMM or RPM modules respectively. Servers must be high quality, fast efficient
machines because, in serving the whole network, they do many times the work of an
ordinary workstation. The file server may use a different operating system from that u
by the workstations. Novell NetWare is an example of a network operating system that
runs only on file servers. The portion of NetWare that does run on the workstation is
there to help DOS, not replace it.


Local Area Network cables come

in different varieties. The customer may use thin
coaxial wire referred to as Thinnet or CheaperNet or thick coaxial wire, Thicknet. He
may use shielded twisted pair (STP), which looks like the wire that carries electricity
inside the walls of your hous
e, or unshielded twisted pair (UTP), which looks like a
telephone wire. He may also use fiber optic cable, this cable uses light to carry the frames
or messages. The kind of wire one chooses will depend mostly on the kind of network
adapter cards they ch
oose and the speed at which they wish to assimilate data.

Cable arrangements, cable layouts: or cable topology is how the computers are
connected one to another. Some cable layouts are known as:

Bus Topology

: most common

Ring Topology

: a single cable

ree Topology

: branching of cables

Star Topology

: all computers connect to central machine

Daisy Chain Topology

: like our ACCESS4000 modules

Net/DDE Introduction to Networking

CTC Parker Automation




There are times when you need various black boxes called HUBS, repeaters, or access
units to build these systems.

**A few companies, such as Motorola, are pioneering a type of LAN that does not
require cables at all. The wireless LAN uses infrared or radio waves to carry the
network signals from computer to computer.**


A network adapter card, like a

video display adapter card, fits into a slot in each
workstation and file server. Your workstation sends requests through the network adapter
to the file server. Your workstation receives responses through the network adapter when
the file server wants
to deliver a portion of a file to you.

Only two network adapters may communicate with each other at the same time on a
LAN. This means that other workstations have to wait their turn if the network is in use.
Adapters range in price from less than $100 to

much more than $1,000. What do you get
for the money ?. Primarily, speed. Most people measure the speed of a network in
megabits per second (
). A byte of data consists of 8 bits, you can divide the
megabits per second rating by 8 to find out how ma
ny millions of characters (bytes) per
second the network can handle. Now that we are really in the weeds, suppose that you
want to transfer and entire 5 1/4 inch diskette worth of data across a LAN. The rated
speed for this example is 4 megabits per seco
nd. Dividing 4 mbps by 8 bits tells you that
the LAN can theoretically transmit 500K (kilobytes) of data per second.


In addition to LAN hardware you must have a network operating system. Just as you
need DOS to manage applications in a sta
alone computer, you need a network
operating system (NOS) to control the flow of messages between stations. In the simplest
case, this network software makes the disk drive of the server appear to be an extra drive
on each workstation, (virtual drive F
:). On some computers, a separate, unattended
computer acts as a file server. This is a
Server based LAN.

On other, smaller LAN's, a
workstation may be both a file server and a workstation at the same time. This is a
to peer LAN

(sometimes called

network operating system
) components on each workstation and on the files
server communicate with each other using a computer language called
One common protocol is IBM's
NETBIOS protocol,

short for
Network Basic Input
t System
. Several vendors besides IBM use NetBios. Another protocol is
Novell's IPX, which stands for Internetwork Packet Exchange.

Net/DDE Networking Interact and DDE

CTC Parker Automation



Using Netbios

Interact Networking can greatly expand the power and flexibility of your application!

You can use networkin
g to organize, manage and update your applications more easily.
Interact Networking products also allow you to turn your plant floor workstation into an
Information Hub, drawing data from the plant floor and sending it to MIS and SCADA
environments. You ca
n also use the Interact DDE Server as a gateway to a AS400 system.

The Network driver facilitates communication between controllers and nodes connected
together using off
shelf network systems such as Novell Netware, Artisoft Lantastic
and others. The
Interact NBIOS driver communicates through a Netbios driver supplied
by the vendor of the network operating system you are using.

Interact Networking is designed to work with all NetBIOS compatible networking
topologies including Ethernet, Arcnet, and Toke
n Ring. The NetBIOS implementation
assures Interact will work with new or existing networks, so Interact Networking can be
easily integrated into any manufacturing facility.

Through Interact’s network aware file system, the NetBIOS Driver, Interact Modem
Driver, and the Interact DDE Server you can:

Connect to and share data between Interact workstations

Transfer data files to remote workstations

Send and restart new applications at a remote location

Log your data files to a central location

Run your Inte
ract applications from a centralized location

Run Interact from a central location

Manage Recipes over a network

even load recipes from a data base

Send plant floor data to the DDE applications in the MIS department

Use the Interact DDE Server as a gatew
ay to AS400 or SQL systems

Connect to the Interact workstations via modem

All this capability means Interact not only meet needs ranging from control panel
replacement to high supervisory applications, but can link all of these levels together
your facility!

Sharing Data Between Interact Workstations

Interact allows plant floor workstations to share data on a Local Area Network (LAN).
This is done via Remote Driver Access. Remote Driver Access allows an Interact
workstation connected to a networ
k to access information residing in an Interact
application running on another station on that network in real
time. Numeric or ASCII
data can be written to or acquired from a programmable controller. It can also be read
from Interact Link variables, for e
xample to monitor the PLC driver status of a remote

Net/DDE Introduction to Networking

CTC Parker Automation




All this is done through a simple addressing format. The picture below illustrates a typical

address which might be assigned to a PTM tool or alarm on Node_A:


In the above example

is used to reference the Netbios driver, signaling the data is
to be acquired over the network.

is the station on the network from which the
data is to be read. The

is an address using the Interact d
emo driver (PLC
controller). An address in the native format of your controller may be used here.

Transferring Data files and Sending Applications

In Run mode Interact Networking supports transferring Interact files and applications to
and from remote Int
eract stations. Typical files might include alarm log files, data logs,
recipe logs and reports. The NetBIOS driver transfer features make it easy to copy files be
over the network. These transfers may also be security protected.

Interact application files

may also be transferred across a network. This makes it possible
to create an application at your desk, download it to a remote station on the network, and
restart that application. All without ever leaving your desk!

Logging to and R
unning Interact from a Central Location

Interact uses many “disk based” files to perform its tasks. Since Interact supports these
features and can read and write to its files from any valid location across a network, its
file system is said to be “network

Interact recognizes two DOS environment variables. They are:


which specifies the drive and directory where
application files exist.


which specifies the drive and directory where Interact
program files exist.

These enviro
nment variables can be very useful in a networked system for centralizing all
applications and/or program files on a network server.

Net/DDE Networking Interact and DDE

CTC Parker Automation



The network aware file system also means any path for logging Interact data files may be
set to any logical drive on the ne
twork. In the example below a typical alarm log path for
Node_A might be
. Node_B might store its alarms to the path


The logging and centralized program files feature are inherent to the Interac
software and do

require the NetBIOS driver.

Managing Recipes Over a Network

Interact’s Recipe Communication Module allows you to use different directories to load,
save and delete recipe files in your application. Plus the network aware file system
xpands that capability over a network. This means separate workstations on the network
can load, save and delete files from the same locations! This greatly enhances the
usability of your recipes by diminishing confusion over which stations hold the most
urrent recipe files.


This feature is inherent to the Interact software and does

require the NetBIOS

Connecting to a SCADA or MIS/MES Environment

In Run mode Interact utilizes the high speed and efficiency of D
OS for plant floor
workstations. However its important to be able to get that plant floor data to all areas of
your organization

like the MIS department. But, many MIS/MES applications require
Windows, and so sometimes slower SCADA packages get forced to

the factory floor in
order to support the needs of the MIS department. This is not where these packages are
Net/DDE Introduction to Networking

CTC Parker Automation




the best fit since process control requires immediate updates that higher level SCADA
packages can’t supply.

The Interact DDE Server allows you to

have the best of both worlds. Through the Interact
DDE Server your can take plant floor information from an Interact workstation and bring
that data into any Windows DDE capable application.

The Interact DDE Server gathers information from plant floor w
orkstations connected to
the Interact NetBIOS network. In the Windows environment the DDE Server then
supplies that live data to DDE capable client applications. DDE client applications may
read from or write to Interact workstation applications.


Gateway SQL Environments

Through the Interact DDE Server data from workstations on the plant floor is brought
into Windows DDE compatible applications. This information can then be manipulated
and imported to AS400 or type of machine that supports SQL. So

Interact allows you to
send data to all areas of your organization, from plant floor workstations to higher level
data base systems. Interact Networking provides you with the complete solution.


Expanding Application Cap
abilities via Modem

The Interact Modem Driver connects Interact workstations over standard telephone lines,
and allows these stations to take advantage of all the features of the NetBIOS Driver. The
Interact Modem Driver also includes an automated dialing
feature that will connect a
remote station based on events, time or operator inputs. For example you could have a
remote station call a supervisory station when an alarm is triggered, and the supervisory
station could then evoke an action to correct the pr