Category Archives: ORCAview Tips

Delta Controls – ORCAview Tip- Analog Totalizer

Analog Totalizer

Analog Totalizers are used to calculate the accumulated quantity of a measured variable according to that measured variable’s rate. For example, by using an Analog Totalizer you could determine how many kWh of electrical consumption you have if you’re measuring electrical demand in kW. To do this you would simply enter the Monitored Object, select Hours as your conversion rate and kWh as your units.

Common Pitfalls in GCL+ Programming (Part 2 – Using And, Or)

In a recent post, we introduced boolean logic and the AND, OR, and NOT operators.  Now we will show some common ways in which these can be accidentally misused in a GCL+ program, and how to correct these errors.

AND

As we saw previously, the AND operator compares two boolean (true or false) statements.  If and only if BOTH statements are true, the entire statement will be true.  This is very commonly used in GCL+ programs.  There are some important things to watch out for, however!

For example, this bit of programming looks just fine, but actually won’t work the way you would expect:

If AHU1_LOW_LIMIT And AHU1_SMOKE = Normal Then

      // Commands we want to execute would be here

End If

Here’s what’s happening.  When you use “And”, GCL+ will evaluate what’s on either side and compare the two things.  If they’re both true, the whole condition will be true.  When it sees AHU1_LOW_LIMIT all by itself, it evaluates it.  In this case, “Normal” is OFF and “Alarm” is ON. In GCL+, ON is the same as true and OFF is the same as false.  So the equivalent is:

If AHU1_LOW_LIMIT = On And AHU1_SMOKE = Normal Then

      // Commands we want to execute would be here

End If

This is the same as:

If AHU1_LOW_LIMIT = Alarm And AHU1_SMOKE = Normal Then

      // Commands we want to execute would be here

End If

As you can see, this is not the intended result.  Here is the correct way to do it:

If AHU1_LOW_LIMIT = Normal And AHU1_SMOKE = Normal Then

      // Commands we want to execute would be here

End If

OR

The same thing applies if you’re using “Or”.  The OR operator compares two boolean statements.  If either of the two statements is true, the overall statement is true.  This is the correct way to do it:

If AHU1_LOW_LIMIT = Alarm Or AHU1_SMOKE = Alarm Then

      // Commands we want to execute would be here

End If

Common Pitfalls in GCL+ Programming (Part 1 – Boolean Logic)

Setpoint Systems has been providing FREE training to our customers for over 25 years, and in that time we’ve learned as well… how to best serve our customers.  We’ve also learned to recognize some of the most common technical challenges our customers face.  I’d like to highlight a few GCL+ programming challenges and solutions.  This post will lay the foundation for future discussions.

We need to start with a brief introduction of boolean logic.  You can follow the embedded link to see the definition in more detail, but in a nutshell here’s what it is:

Boolean logic (boolean algebra), is all about statements being either true or false.  This is fundamental to how computers and programming work.  True can also be thought of as 1 and false as 0.  A question can be asked and the answer is either true or false.

Courtesy of Sue's Blog Spot: http://suesauer.blogspot.com/

Courtesy of Sue’s Blog Spot: http://suesauer.blogspot.com/

For example, we might want to know if the weather is nice outside.  We can’t ask a computer or DDC controller if the weather is “nice” though–it would have no idea what we mean.  We must ask specific questions with true or false answers, like “Is the outside temperature above 60°F ?”  But the way boolean logic works, we represent our question in the form of a statement that can be evaluated as true or false.  This would look like “Outside Air Temp > 60”.  So far so good, right?

But what if it gets too hot?  We need to add more criteria to our question.  Perhaps we’d like to ask “Is the outside temperature is between 60°F and 85°F ?”.  What would that look like if we wanted to ask a DDC controller?  We now have TWO criteria that both have to be true.  It has to be above 60°F AND below 85°F.  This introduces the boolean operator “And”.  When we use “And”, the statements on either side must both be true in order for the whole statement to be true.  If either statement is false, the whole thing is false.  Our statement would now look like “(Outside Air Temp > 60) AND (Outside Air Temp < 85)”  I’m using parentheses to emphasize the two statements that are being compared by AND.

Another commonly used boolean operator is OR.  If you want EITHER statement to be able to make the overall statement true, this is what you use.  For example, we might ask “Is the outside temperature is between 60°F and 85°F OR is the outside relative humidity below 75% RH ?”  This would be shown as “((Outside Air Temp > 60) AND (Outside Air Temp < 85)) OR (Outside Relative Humidity < 75)”.  Again, note the use of parentheses to indicate the order of operations.  This is especially important if you mix AND along with OR in the same statement.

Finally there’s NOT.  This one is fairly simple–it reverses true to false and false to true.  For example, if I wanted to know if it wasn’t raining outside, I could ask “Is it NOT raining?” which would be shown as “Not(Raining)” where “Raining” is a boolean true/false value that lets me know when it IS raining.  Making sense or NOT(making sense)…?

I hope this has been informative.  It lays the foundation for upcoming discussions of GCL+ programming tips.  Stay tuned for more!

Delta Controls – ORCAview Tip – User Activity Log

JOHN

Did you know you can log user activity on your workstation? While logged in to ORCAview, click on the “Tools” menu and choose “Setup” and then “Site…” Click on the “Advanced” tab and set User Logging to High. This will track all user activity on that workstation (enable on all workstations for complete coverage) to a file called UserLog.txt which will be located in the

  • C:\Program Files\Delta Controls\3.xx\Sites\your_site_name\ directory (C:\Users\Public\Delta Controls\e\ if you have 3.40 software). “3.40\Sites\your_site_nam

Delta Controls – ORCAview Tip – Save graphic to HMI

HMI

Graphics for the enteliTOUCH touchscreen are very easy to load!  Highlight one or more graphics in the Navigator, right-click, and choose “Save as HMI Page…”  Graphics are transferred across the network, so you don’t have to go to each one individually.  This is a huge time-saver!

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Delta Controls – ORCAview Tip – Set Controller Clock (one)

To set the internal clock in a controller, select the controller in the left-hand pane of the Set Controller TimeNavigator window and choose “Set Controller Time” from the Tools menu.  A dialog box will appear allowing you to adjust the time and date before setting the controller’s clock.  The current date and time will automatically be obtained from your workstation’s clock.

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Delta Controls – ORCAview Tip – Auto-Logoff

The Auto-logoff period is the amount of time that ORCAview will sit idle before automatically logging off of the network. You can disable this feature by setting the period to 0 on the “Login” tab of your System User Access (SUA) Object.

Orca 2

  • To get there, go to the “Tools” menu, select “Setup”, and then “Current User…”
  • Click on the “Login” tab, and you’ll see something like the picture on the right.
  • The Auto-logoff period can be changed at the bottom.