OPC Server


Thread Starter

Zheng YiBing

Is there any body who can tell me how can I develop a OPC Server for
my control equipment?
Where can I find OPC lib, something like that?

ABB Bailey Beijing,
Zheng YiBing.
USe the Iconics OPC Server toolkit, It allows your to quickly develop the
driver, and handles all of the OPC interface requirements.

Rick L. Hudson EMCO Inc.


I have used OPC Server software from www.softwaretoolbox.com (specifically
OMRON PLC's - in conjunction with Intelluion iFix via Ethernet - CS1- and
Serially - C200H). They have free demo downloads. The same software can be
used with VB. They are a great bunch to work with.

Rick Hudson
Hi Zheng

You can take two roads here. Either you can develop your own OPC server, or
you can purchase one.

Two companies that I am aware of have OPC drivers for Bailey Net90 and
Infi90 systems:

Matrikon Inc., Edmonton, Alberta, Canada

The RoviSys Company, Aurora, Ohio, USA

You might find the purcahse route to be more cost effective than

Jack Rainey

Peter Whalley

Hi All,

I have received a couple of comments in the past few days suggesting that
OPC servers are limited to a maximum of 1000 (or so) tags on a single
server. Is this a real limit with all servers or is it just a limit with
some particular servers. One suggestion was that some OPC servers actually
use an underlying (legacy) DDE server and that DDE has a limit of 1000
items. Has anyone come across this problem.

Thanks for your thoughts.

Peter Whalley

Magenta Communications Pty Ltd

Melbourne, VIC, Australia

e-mail: peter*no-spam*@magentacomm.com.au
delete *no-spam* before sending


Dear all,

any knowledge of an OPC driver for Bailey infi90 "infinet loop(redundant)" protocol?


Arifeen R Qadeer
I've never heard of tag limits other than those imposed as a part of a graduated licensing program. Some SCADA packages have claimed "unlimited" tag capability while others top out at 10,000 or so.

Hello Peter,

No, there are no such limits imposed on OPC servers by the specification, or by the enabling technology (i.e. COM/DCOM). The 1000 point limit you've heard about would be particular to a given server. Perhaps, it's a limitation imposed by the vendor's licensing scheme, or bandwidth
limitations in the communications path to the underlying system/device.

Best regards.
Gord Ellis

Gord Ellis, P.Eng.
Northern Dynamic Inc.
J103-155 Frobisher Drive
Waterloo, Ontario
Canada N2V 2E1
Tel/Fax: (519) 725-2071/2072

Peter Whalley

Hi Dale,

The problem seems to be in separate OPC Server software (eg LonMark to OPC servers) rather than the SCADA software itself but some servers may also have tag limits as part of the licensing.

Thanks for your comments.

Peter Whalley

D. C. Pittendrigh

Hi All

I have set up several OPC servers using the Siemens OPC server available with their Ethernet interface cards for PC's and in at least 3 instances am successfully accessing close to 3000 tags in 250 to 300ms update time.

Donald Pittendrigh


Peter Whalley

Hi Ralph,

Thanks for your comments.

I've been looking at the NLOPC server from Newron System and discovered deep in the documentation that when you enter the software key to activate
the software you also enter a capacity number which is the number of tags that the software key licenses. Failure to license enough tags may be one cause of the reported problems.

I've also found that NLOPC has a check box on the main configuration screen which determines how the server initialises items. If this is configured to try and read all values on initialisation then it could cause problems with
large tag counts particularly with LON networks which can have servere limits on polling rates.


Peter Whalley

Peter Whalley

Hi Donald

Thanks for the comments. I had a simalr comment from someone at Siemens suggesting they had run up to 50,000 tags on a server so the 1000 pont
limit I've heard about seems to be either an initilisation problem or a licensing issue.


Peter Whalley