Allen-Bradley InView Marquee 2706-P42, User Manual

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Publication 2706-UM016A-EN-P - June 2002
InView Control InView Control API 10-7
Heartbeat
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Syntax - object . Heartbeat = value
Read/Write [short]
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Values - 0 - No heartbeat from control
1 - Heartbeat generated by control
2 - Heartbeat disabled
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Default - 0
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Description - This property is used to set how the control will
handle the heartbeat requirement of the display. The display
requires serial activity approximately every 3 seconds. In the
absence of such activity the display will show a “No Network
Activity” message. If the heartbeat property is set to 0, the
activity is assumed to come from sources such as variable
updates. If the heartbeat property is set to 1, the control will
generate a serial “heartbeat” command that prevents the display
from displaying the no activity message. If the heartbeat
property is set to 2, the need for constant serial activity will be
disabled in the display.
Methods Initialize
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Syntax - HRESULT Initialize ()
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Parameters - None
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Return Value -S_OK - Success
E_FAIL - Failure
•
Description - This method is used to open the COM port or
socket that will be used to communicate with the display. If
Initialize is called more than once, any open connection will be
closed, and a new connection opened.
Close
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Syntax - HRESULT Close ()
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Parameters - None
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Return Value -S_OK - Success
E_FAIL - Failure
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Description - This method is used to close any open
connection to free its resources for other applications. Any open
connection is automatically closed when the control is
unloaded.
Allen-Bradley Spares