Applies To:
  • CitectSCADA 5.x

Summary:
How are Points counted in Version 5.0? 

Solution:
Citect Version 5.0 now has static and dynamic points.

Static are tags which are statically bound. These are tags in the Pages, Alarms, Trends, Reports, Cicode, Events, etc.

Dynamic tags are tags which are dynamically bound. These are tags which are defined in the VARIABLE TAG database, however they are not used as static tags. They are used when you bind to a Super Genie, Use the TagRead, TagWrite Cicode functions, read from them via DDE or CTAPI or ODBC. Write to them via DDE, CTAPI, ODBC (including memory/disk based tags).

If you have real I/O Points then the demo mode will run for 15 minutes with a maximum IO count of 50,000.

If you have no real I/O Points then the demo mode will run for 10 hours with a maximum IO count of 1. This will impact if you have DDE or CTAPI code which writes to internal tags. When you write to an internal tag it counts as a point. So it will allow you to write to one point. The next write will fail, as you have used up your dynamic points. If you want to run DDE or CTAPI code in demo mode with no physical PLC, you will need to configure a real PLC and place one static tag in it. Put the tag in Cicode or a page, it does not have to be accessed. When you startup Citect, the I/O Server will try to communicate to the PLC and give you a hardware error if it does not exist. You can prevent this by disabling the I/O Device with the IODeviceControl() command.

OEM Special keys allow 42,000 points and will run for 8 hours with real I/O Points.

Normal keys are available in a variety of point sizes. For example a 5,000 point key will allow you to run for ever with reading up to 5,000 I/O points from a real I/O Devices. Points are counted if there data is coming from outside of Citect. This is the case with physical I/O Devices or if they are internal points and they are being written to via an external application. For example if you write to a DISK tag via DDE from Excel this will count as a point. If you exceed the maximum number of points the DDE Write or Poke operation will fail. Citect will not shutdown it will continue to run.

If you reach the point limit with static points then Citect will not startup. If you reach the limit with dynamic points, Citect will continue to run, however you will not be able to use any more dynamic points. This will mean any new references to tags via Super Genies, DDE, CTAPI, or ODBC will fail.

 

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