An I/O scan list is a configuration table that identifies the targets with which repetitive communication is authorized. While the CPU is running, the Ethernet module transfers data to and from the CPU’s registers in accordance with I/O scan list.
The I/O Scanner opens one connection for each entry in the I/O scanner table. If several table entries have the same IP address, multiple connections are opened.
The I/O Scanner on the BMX NOE 01x0 modules are limited to:
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maximum number of devices: 64
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maximum number of input words: 2048
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maximum number of output words: 2048
Using the I/O Scanner across a Network Router
The I/O Scanner can scan devices through an IP router with a TTL (time to live) of 32.
Remote input/outputs are scanned periodically depending on the application requirements. A scanning period is defined for each device through configuration, according to the update speed.
NOTE: Keep in mind:
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The lower the scanning period, the faster the input/outputs are updated. However, this speed increases the network load.
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%SW8 and %SW9 do not stop remote station scanning, but inhibit the copying of I/Os to and from the application variables.
