Delta AS Series Programming Manual page 164

Example:
1. Determine the Ethernet communication quality
Step 1: Check if the value in SR1019 is 0.
SR1019 = 0 Good communication quality
SR1019 > 0 Error occurred during communication, go to step 2
Step 2: Check the current values in SR1017 and SR1018
Communication quality is good; set the value in SR1019 to 0. If the error occurs from time
to time, ask your network administer to check if there is any device that can cause
SR1017 < SR1018
communication error in the network.
If the value in SR1019 is NOT 0, it indicates the communication is not normal. You need to
lower the workload of data exchange or refresh the network capacity.
The values in
SR1017 and SR1018
are close
2. Refresh the network capacity
◆
When you raise the value in SR1017, the value in SR1019 should also be raised. But if the value in
SR1019 stays the same and the values in SR1018 and SR1017 are quite close, that indicates the
communication workload is almost full. It is suggested to raise a value that is at least 5 times bigger
compared to the SR1018 value in SR1017. You need to clear the value in SR1019 to see if it works
whenever you change the value in SR1017.
◆
When the network traffic is heavy, if you raise the value in SR1017, evey 10 more increased value, adds
around 2.2 ms more on the scan time. (the test environment: no extension module, no RTU or data
exchange table.) Therefore, after the value in SR1017 is raised, you need to pay attention on the scan
time. If the network traffic is not too heavy, the value in SR1017 will not affect the scan time too much.
However, if the network is abnormal, CPU uses more resources on the packet handling and that will
increase the scan time. You need to consider the network workload and the scan time, when you set the
value in SR1017.
◆
If the packets cannot be handled in the allowable scan time, you can consider the followings to lower the
network workload.
 Decrease the network connections with the CPU, for example, decrease the data exchange numbers
via Modbus TCP or EtherNet/IP.
 Lower the refreshing rate in data exchange, for example lessen the refreshing cycle for data exchange
via Modbus TCP, or increase the value in RPI for data exchange via EtherNet/IP.
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