Verifying The Network Bandwidth; Checking The Network Bandwidth Used For Safety I/O Communications - Omron DEVICENET SAFETY - CONFIGURATION MANUAL 05-2005 System Configuration Manual

3-2

Verifying the Network Bandwidth

Approximately 100% of the network bandwidth in the DeviceNet can be used. If the setting exceeds the ac-
ceptable bandwidth, however, timeouts will occur.
This section describes how to check the network bandwidth used for safety I/O communications in the de-
signed network and how to calculate EPI from the usage rate of the set bandwidth.
3-2-1

Checking the Network Bandwidth Used for Safety I/O Communications

In the lower portion of the network window, the Network Configurator displays the percentage of the network
bandwidth used for safety I/O communications from the connections set in the virtual network.
The percentage of network bandwidth used is displayed for each baud rate.
Performing Only Safety I/O Communications
When performing only safety I/O communications, there is no problem if the network bandwidth used for safe-
ty I/O communications is approximately 90%.
If bandwidth exceeds 90%, obtain the average EPI by referring to the next section and use it as the reference
for setting connections.
IMPORTANT:
Performing Safety I/O Communications and Standard I/O Communications
When both safety I/O communications and standard I/O communications are mixed on one network, it is nec-
essary to determine the network bandwidth to use for each communication. In this case, check that the net-
work bandwidth used for safety I/O communications does not exceed the determined value.
The Network Configurator can calculate the average EPI by the user entering the network bandwidths to use
for communications. Set the EPI for each safety connection and the communications cycle of the Standard
Master referring to this value.

3-2 Verifying the Network Bandwidth

Keep 10% or more space in the network bandwidth for establishing a connection and for
communications of the Network Configurator. If the user application uses explicit message
communications, additional network bandwidth is necessary. In this case, decide the net-
work bandwidth for the explicit messaging in consideration of the amount of the data and
the frequency of the communications.
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