Omron NX-SIH400, User Manual

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Precautions for Correct Use
If you change any of the following values, the minimum safety task period will change. Check
the minimum safety task period again.
• Safety program execution time (This time depends on the sizes of the programs and the func-
tion blocks that are used.)
• Number of connections with FSoE slave devices
• Number of connections with CIP Safety devices
8-2-4
Setting the Safety Task Period
This section describes how to find an approximation of the value to set for the safety task period.
Use the following formula to find the safety task period.
Safety task period = "Minimum safety task period" + "Expansion communications monitoring time"
If the calculated value exceeds 100 ms, adjust the value to be less than 100 ms.
Refer to 6-5-8 Safety Task Settings on page 6 - 66 for information on setting the safety task period in
the Sysmac Studio.
l
Expansion Communications Monitoring Time
The expansion communications monitoring time represents the additional time to wait for recep-
tions in safety process data communications. You can set an expansion communications monitor-
ing time to help prevent timeouts in safety process data communications when noise on the com-
munications path or other factors result in communications retries.
Set this time as required.
l
Finding the Expansion Communications Monitoring Time
The method to find the expansion communications monitoring time depends on the NX bus master
that is connected.
• NX Units connected to an CPU Unit or EtherCAT Coupler Unit
The method to find the expansion communications monitoring time depends on the Unit that is
connected.Set the expansion communications monitoring time to at least the length of the Ether-
CAT Coupler Unit communications timeout value and to an integer multiple of the slave control
period of the Safety I/O Units.
• NX Units connected to an EtherNet/IP Coupler Unit
Set the expansion communications monitoring time to an integer multiple of the slave control pe-
riod of the Safety I/O Units.
(a) Slave Control Period of a Safety I/O Unit
Use the following value for the slave control periods of the Safety I/O Units.
Model Slave control period
NX-SIH400 6 ms
NX-SID800 3 ms
NX-SOH200 3 ms
NX-SOD400 3 ms
(b) Communications Timeout Value of an EtherCAT Coupler Unit
8 Calculating Safety Reaction Times
8 - 7
NX-series Safety Control Unit User's Manual (Z930)
8-2 Safety T
ask
8
8-2-4
Setting the Safety T
ask Period