Omron CX-SUPERVISOR - SCRIPT REFERENCE REV2.0, Reference Manual

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OMRON APPENDIX D – Obsolete Features
Revision 2.0 Page 157
Note 3: The Granularity (or intervals) differs between Operating Systems. In Windows NT
(and 2000) expiration is checked every 10ms, so
'Sleep(100)
' actually pauses for
any time between 100 to 109.99 milliseconds depending on when it was started. For
Windows 98 (and ME) the granularity is 55ms so
'Sleep(100)
' actually pauses for
110 (2 times 55) to 164.99 milliseconds (nearly 3 times 55). For this reason, Sleep
statements can act differently on different Operating Systems making the application
OS dependant.
Note 4: Sleep should never be used as a delay for timing processes, for the following reasons:
- The actual time delay depends on the OS as described above
- There is always an error of 0 to 1 granularity, depending on when the action is
started.
- The frequency can not be guaranteed as the OS may be busy, or handling other
processes.
DDE Commands
DDE as a means for exchanging data has now been obsolete for some years. In fact for so long even
its successor, OLE Automation is obsolete. DDE has also proved to be a poor technology, suffering
from unfixed memory leaks both in the native Operating Systems, and tools like Microsoft Excel.
This technology has now been replaced and the CX-Supervisor Communications Control should be
used instead.
The following DDE script commands are obsolete.
DDEExecute
Syntax
returnstate = DDEExecute(channel, {command})
Remarks
Argument Type Description
returnstate Bool Returnstate is ‘1’ if the function is successful, or ‘0’ otherwise.
channel Integer
point
This is an integer point which contains the return value of the
DDEInitiate() command. Both server and topic parameters
applied to the channel based on the DDEInitiate() command
must be open or an error is reported.
command String This is a command as recognised by the server application
specified within the channel .
Typical Example
channelname = DDEInitiate("Excel", "Sheet1.xls")
DDEExecute(channelname, {[OPEN("C:\EXCEL\WORK\SHEET2.XLS")]})