Scanned peripheral devices are configured in a table that is used to:
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list remote devices to be scanned, using the IP address
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specify the time out for each remote device
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specify the scanning period allotted to it for each remote device
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configure, for each device, the amount of space the input and output words take up in the read and write zones
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set the output fallback mode for each device
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add comments for each device
The IP Address and Unit ID Fields
The IP Address field is used to list the devices which must be scanned by the Ethernet module.
The Unit ID field is used to associate the slave address of the device connected to an Ethernet/Modbus gateway with the IP address:
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values are from 0 to 255
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the default value is 255
The Health Time out field is used to set the maximum interval between 2 responses from a remote device, from 1 to 50000 ms. Beyond this time limit, the Health bit switches to 0.
The
Repetitive rate field is used to associate an IP address with its
scanning period, from 0 to 50000 ms.
Master RD Ref. and Master WR Ref.
These parameters give the addresses of the beginning of each range reserved for the device.
These parameters cannot be accessed. They are calculated automatically as the sum of:
Example
The Ethernet module scans two devices:
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a Momentum at the address IP1, which has 4 input words
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a Momentum at the address IP2, which has one input word
Furthermore, the read field address starts at %MW100.
In this case, master RD ref. for the address IP1 equals 100. The internal word range reserved for the address IP1 starts at %MW100 and is made up of 4 words.
Therefore, master RD ref. for the address IP2 equals 104. The internal word range reserved for the address IP2 starts at %MW104 (=%MW100 + 4 input words).
Slave RD Ref. and Slave WR Ref.
These fields correspond to the indices of the first word to be read and written for remote devices to be scanned.
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slave RD ref.: specifies the address of the first word to be read
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slave WR ref.: specifies the address of the first word to be written
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Read Length and Write Length
This field is used to configure the behavior of inputs in the event of an access error in relation to the remote device (example: cut-off of the device, etc.):
This field is not used by the module. It is only used to locate the device in the configuration more easily.
It has a maximum size of 32 characters.
