Points
SECTION 20 Best Practices
266
1. Group together points that will be configured as "Always Update" in
contiguous PLC memory addresses
2. Group together points that will be configured as "Update when On
Display", grouping for each page
3. Within groups from steps 1 & 2, create sub-groups for each required
update rate
4. Within update rate sub-groups, sort and group data by data format (BCD,
Float etc). These points can be defined as 1 or more arrays.
20-2-1-1 Use Fins event memory
If your communications is using a Fins driver (e.g. Controller Link) it is possible
to create a responsive application giving the impression of high performance
by linking the SCADA to the event memory, which the network updates
automatically. Of course reads and writes actually access the local cache very
quickly although this will lag behind actual device values.
20-2-1-2 Control communications
Use the 'On Request' update type to give you complete control over when the
value of a point is read from the PLC or written to the PLC. The 'InputPoint'
script function is used to input the value of a specified point and the
'OutputPoint' script function is used to output the value of a specified point.
20-3
Points
This section covers some good practices with the Points for quicker
development and smoother running.
•
Define as few points as possible
Keep the Points database as slim and manageable as possible by:
•
Using arrays where possible especially for PLC points
•
If memory points are defined for scripting try to reuse general
purpose points like 'nLoopCounter', 'bReturnValue', 'nTemp'
•
Use expressions in animations instead of calculating new values e.g.
using "Temper 273" rather than creating a new
"TemperatureCelsius" memory point.
•
For memory areas that are bit and word addressable, access as
words. If you want the bits use expressions with & and | operators
e.g. Display Digital animation expression 'MyW100 & 0x80' and
'MyW100 & 0x40' instead of 'MyW100bit8' etc.
•
Reduce the number of active points
Aim to reduce the number of active points, that are currently
communicating where possible:
•
Automatically by setting "Update when on Display" option
•
Manually using script (EnablePoint(), DisablePoint(), OpenPLC(),
ClosePLC() etc).
•
Have a minimum of Input/Output points
Double-check the use of all Input/Output points. Don't forget that 'Output'
points can actually have 'Data Transfer' set to input the value only once on
start up.
•
Use ‘Standard’ update rates
Summary of Contents for CX-Supervisor
Page 1: ...CX Supervisor Software Cat No W10E EN 01 User Manual Software Release 3 1...
Page 3: ...Copyright Notice 2...
Page 16: ...15...
Page 17: ...16...
Page 27: ...Tip of the Day SECTION 1 Graphics Editor 26...
Page 35: ...CX Supervisor Preferences SECTION 2 Pages 34...
Page 79: ...Responding to Events SECTION 5 ActiveX Objects 78...
Page 115: ...Printing the Graphics Library SECTION 7 Graphics Library 114...
Page 181: ...Data Logging SECTION 11 Data Logging 180...
Page 201: ...Examples SECTION 12 Databases 200...
Page 243: ...Performance Monitor SECTION 16 Application Analysis Performance Monitor 242...
Page 253: ...Using with Omron s CX Server OPC SECTION 17 Using CX Supervisor as an OPC Cli 252...
Page 259: ...Creating a CX Supervisor Client application SECTION 18 Connecting to a remote CX 258...
Page 263: ...Adding a Point Linked to a Parameter SECTION 19 Connecting to Omron Industrial 262...
Page 271: ...Data Logging SECTION 20 Best Practices 270...
Page 275: ...Configuring a Server PC running Windows NT or 2000 Appendix A Configuring a PC 274...
Page 277: ...Appendix B Frequently Asked Questions 276...
Page 296: ...Appendix B Frequently Asked Questions 295...
Page 297: ...Appendix B Frequently Asked Questions 296...
Page 298: ...Appendix B Frequently Asked Questions 297...
Page 299: ...Appendix B Frequently Asked Questions 298...
Page 333: ...Revision history 332...