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How Can I Programmatically Disable All Polling for My Lookout Driver Object?

Primary Software: Lookout
Primary Software Version: 5.0
Primary Software Fixed Version: N/A
Secondary Software: N/A

Problem: I need to modify my Lookout process without having the PLC attached, but this always causes communication alarms. Is there a way to switch between having a polling rate and having polling completely disabled?

Solution: This is simple to create for driver objects that have a poll data member:

1. Create a switch (i.e. switch1) to enable and disable the polling;
   
   
2. Create a pulse timer (i.e. timer1) to control the polling rate;
   
   
3. Create an expression for the poll data member of the driver object as follows:
   
   driver.poll = switch1.value AND timer1
   
   This expression provides a polling rate and a way to disable;
   
   
4. To prevent any initial alarms, you must create an INI file for your driver object (modbus.ini for Modbus, tiway.ini for Tiway, etc.) in the Lookout directory and create the following entry in it:
   
   SkipImmediatePoll=1

Once you have made these changes to your Lookout process, you should be able to enable and disable periodic polling with the newly created switch object.

Related Links: KnwoledgeBase 2L7EGB5F: Modbus INI File Settings
KnowledgeBase 2A3ENCLS: Where can I Find Drivers for Communicating to PLCs, RTUs, and Other Industrial Hardware?

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Report Date: 04/22/2003
Last Updated: 05/13/2005
Document ID: 2WL8A4P6

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