Omron DEVICENET SAFETY - SYSTEM CONFIGURATION 07-2009 System Configuration Manual page 156

Safety Connection Settings
IMPORTANT Set the EPI for each safety connection longer than the Safety Network Con-
122
The cycle time will be longer if safety logic programming has been cre-
ated and will depend on the size of the programming. (Refer to the 11-
2 Operational Flow and Cycle Times in the Safety Network Controller
Operation Manual (Cat. No. Z906-E1-07 or higher).
The Safety Controller cycle time can be checked under Cycle Time on
the Mode/Cycle Time Tab in the Edit Device Parameters Dialog Box,
once all parameters have been set and programming completed. (Re-
fer to 5-6 Setting the Operating Mode and Confirming the Cycle Time.)
The EPI set here affects the network bandwidth usage rate and the network
reaction time.
• Network Reaction Time:
Displayed under Reaction Time in the Data Expected Packet Interval (EPI)
Field. Refer to 2-3 Calculating and Verifying the Reaction Time and 11-5
Reaction Time in the Safety Network Controller Operation Manual (Cat.
No. Z906-E1-07 or higher) for information on the network reaction time.
• Network Bandwidth Usage Rate:
Displayed under Usage of Network Bandwidth for Safety Connections at
the bottom of the Network Configuration Window.
The network configuration may need to be reconsidered if the acceptable net-
work bandwidth usage rate (must be 90% or less overall) cannot be obtained
with the EPI setting required to achieve the required network reaction time.
Refer to 2-2 Allocating Network Bandwidth Usage and Calculating the Best
EPI for details.
troller cycle time. An error will occur when the safety connection parameters
are downloaded if the EPI is shorter, and the download will fail.
Note Calculate the best average EPI for all connections using the following
procedure and batch set the EPI to all devices.
1. Click the Calculate EPI Button under Usage of Network Bandwidth for
Safety Connections at the bottom of the Network Configuration Window.
2. Input the network bandwidth to be used in the Safety Connections Field
and click the Calculate Button.
3. The best average EPI for all connections will be displayed under Best Av-
erage EPI.
4. Click the Update Device Configuration Button.
5. Select the baud rate to be used in the Update Device Configuration Dialog
Box and click the OK Button.
The best average EPI for all connections will be batch set as the EPI in the
safety connection parameters for all devices.
Configurator version 1.6@ has an automatic EPI adjustment function. The EPI
that is set in the device parameters is compared to the actual cycle time. If the
EPI setting is shorter, it will be automatically updated. If the EPI is shorter
than the device parameters, the following warning will be displayed.
Click the Yes Button in the above dialog box. The EPI for the applicable con-
nection will be automatically changed to the device cycle time.
Section 5-1