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OPCcalc® is a
vendor-neutral, process calculation framework for OPC data.
Built with over 20 years of calculation engine design experience,
Exele OPCcalc allows those with process knowledge to quickly create robust
calculations.
Solid performance, unmatched
flexibility, and reliable results are why some of the world's
largest companies reliably use our process calculation products.
Try OPCcalc for free
Current release:
3.4.0 |
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Quick links:
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Product Overview |
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OPCcalc allows you to easily
create process calculations that use OPC
tags as equation inputs and outputs.
Built on
the Microsoft®
.Net Framework and Visual Basic, OPCcalc handles all of the "plumbing" for
your equations, letting you concentrate on your calculation logic.
OPCcalc is an open calculation
"framework", shielding calculation authors from the complexities of
custom programming, yet giving users the option to access and use
all features of Visual Basic.Net (variables, loops, if..then..else,
user functions) and the .Net Framework (relational databases, file
read/write, Web Services, XML etc.).
OPCcalc is more than just an OPC calculator.
It brings
unmatched performance and features to OPC-based calculations.
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Programmers and non-programmers can easily use
our Equation Editor to define
the logic and arithmetic needed for their
equations. OPCcalc will
then build a compiled Microsoft Visual
Basic .Net program
that contains the
necessary OPC calls,
scheduling, and error handling required to execute
your equations on a
configured interval, outputting the
results to other OPC tags.
Each equation library contains one or more equations (outputs) and
can communicate with tags on multiple OPC Servers. Our Equation
Scheduler allows you to configure, start, stop and monitor your
equations.
Once started, you can easily view the details of running
equations (inputs, outputs, errors) with OPCcalc's built-in Library
Snapshot utility.
Example OPCcalc logic in the Equation Editor:
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Visual Basic
OPCcalc uses the .Net Framework's MSBuild
compiler "under the hood" to
create the calculation executables.
Although Visual Basic.Net 2005 is not required for building OPCcalc
equations, some features require that you have a version of Visual
Basic.Net 2005 installed on the OPCcalc computer.
OPCcalc supports the
following versions of Visual Basic.Net:
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Requirements |
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Operating
System: Windows 2000, XP, 2003, Vista
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Compiler:
.Net Framework 2.0.
Optional, but recommended: Visual Basic.Net 2005 (VB Express 2005 free edition supported)
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OPC Server(s):
OPC DA Server (supporting Data Access version 2 or later)
OPC HDA Server, optional (supporting Historical Data Access
version 1.1)
OPCcalc
can communicate with OPC DA and HDA Servers
located locally or across the network.
If your OPC Server
supports DA, you can retrieve and output current values. If your
OPC Server supports DA and HDA, you can retrieve and output
current and historical values. If your OPC HDA Server supports
aggregates (average, min, max), OPCcalc has a set of built-in
functions for retrieving these values directly into your
calculations.
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Product
Components |
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OPCcalc consists of
the following components
Equation Editor
with built-in functions for tag access, aggregates (avg, min,
max, ...)
Equation
Scheduler for configuring and monitoring equation libraries
Equation Server
Service responsible for starting and stopping libraries
Equation
Database allows you to to search equations based on various
criteria
Equation TestMode
Viewer to monitor the output of libraries running in test mode
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Steps required
to build equations |
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To create equations,
you will need to
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Example
Equation Library Code |
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Click here to see a
sample OPCcalc equation library
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Why use OPCcalc? |
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OPCcalc allows you
to read and write data to one or more OPC Servers with minimal
effort. You simply enter the logic in a VB.Net-like syntax using the
OPC tag names directly in your equations.
Click here to see a sample OPCcalc
equation library
Normally, you would
use a programming language (such as C, C++ or Visual Basic) and
underlying OPC calls to develop such equations. Using OPCcalc, you
only need to provide minimal information for the equation including:
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Name of the OPC
tag to receive the result of the equation
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Name of OPC
tags, variables, functions and constants used in the equation
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Associations to
be made between the OPC tags, variables functions and constants
The above
information is stored in one or more text files called OPCcalc
libraries. Once you have provided this information in a library,
OPCcalc builds a compiled Visual Basic .NET executable that will
perform the calculations and output the results to OPC tags on the
OPC Server.
OPCcalc will
dramatically cut your development time and easily allows
non-programmers to create complex calculations that read and write OPC data.
Standardizing:
OPCcalc gives you a standard method for
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Connecting to
one or more OPC servers
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Accessing
current (DA) and historical (HDA) values
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Handling lost
connections
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Retrieving tag
values
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Writing tag
values
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Providing
application error handing
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Scheduling
execution
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Performing
aggregate function calls (average, min, max, ...)
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Code
documentation
Advantages:
Using OPCcalc offers many advantages:
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Can
significantly reduce the number of lines of code
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Accepts OPC tag
names directly in logic
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Automatically
codes equation run-interval and startup logic
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Generates
uniform and easy to maintain program
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Multiple debug
options including built-in snapshots of running equation
inputs and outputs
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Built-in
functions for current, historical and aggregate OPC tag values
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Support for
user-defined functions and subroutines
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Local variables
that retain their values between executions (allows you to
reference values from previous runs)
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Order-of-execution control for all equations in a library
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Equation results
can be tested over multiple executions before equations are
deployed
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Built-in
calculation diagnostics (latest completed execution and
execution times)
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Remote
monitoring, starting, and stopping of calculations
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Access to the
entire VB.Net language (math function, language structure,..).
Because you can
easily move data into and out of one or more OPC Servers, OPCcalc
can be used to quickly create interfaces to/from/between OPC Servers
and other data sources (relational databases, etc).
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OPCcalc and Visual Basic.Net
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Click here for more information on Visual
Basic.Net
Because OPCcalc creates a VB.Net
executable, you can take advantage of this rich language within your
equation logic. This includes things such as
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Access to the
entire Visual Basic language
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Support for
user-defined functions and subroutines
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Ability to call
external assemblies and Web Services
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Use of Visual
Basic constructs (If..Then..Else, Arrays, Variables)
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Retrieval of
values from relational databases (Oracle, SQL Server, Access,
...)
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Outputting of
data to relational databases
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Reading and
writing of files
Download
Visual Basic
2005 Express (free!)
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