Omron DeviceNet Safety, Руководство по настройке системы

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Allocating Network Bandwidth Usage and Calculating the Best EPI Section 2-2
IMPORTANT The minimum possible EPI setting is larger value of either the Safety Network
Controller cycle time or the Safety Slave cycle time (fixed at 6 ms). The mini-
mum possible EPI will be affected, therefore, if the Safety Network Controller
cycle time is longer than 6 ms.
8. Reconsider the network configuration itself if you have performed the test
calculation as outlined above and either of the following occur, i.e.,
•
the desired best average EPI for each safety connection and the best
communications cycle time for the Standard Master cannot be calculated,
or
•
the Safety Network Controller cycle time is longer than the best average
EPI.
Consider adjusting the following aspects of the network configuration.
•
Reducing the number of nodes or I/O points.
•
Splitting the network
• If using both safety and standard I/O communications, split the net-
work into a DeviceNet Safety network and a standard DeviceNet net-
work.
• If using only safety I/O communications, split the network into two De-
viceNet Safety networks.
9. Change the EPI settings for each safety connection and the Standard Mas-
ter communications cycle time setting to suit the desired baud rate.
• Changing the EPI Settings for Each Safety I/O Connection
The best average EPI calculated is the best average of all safety connec-
tions.
The following method is used for setting the calculated EPI as the EPI in
the parameters for all safety connections.
• Method for batch setting the best EPI to devices
a. Click the Update Device Configuration Button.
The Update Device Configuration Dialog Box will be displayed.
b. Select the baud rate to be used and click the OK Button.
The calculated best average EPI value will be batch set as the EPI in
the safety connection parameters for all devices.
c. If required, adjust the EPI settings for the whole network, making the
EPI smaller for those connections that need a faster response time
(e.g., for safety curtain connections) and making the EPI larger for