HMS Networks Anybus CompactCom 40 Network Manual page 54

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Anybus CompactCom 40 - PROFINET IRT Transparent
Ethernet
10.4.6. Command Details: Map_ADI_Write_Ext_Area
Details
Command Code: 12h
Valid For: Instance
Description
This command is only supported by Anybus CompactCom 40 devices.
This command is equivalent to Map_ADI_Write_Area, but can map more than 256 bytes of data. It supports
mapping fractional byte size types, and it can be used to map only specific parts of an ADI.
It maps an ADI as Write Process Data. If successful, the response data contains the offset, in bits, for the mapped
ADI from the start of the Write Process Data area.
• Mapping an ADI more than once (i.e. map it multiple times to the Read- or Write Process Data, or map it to
both the Read- and Write Process Data) is not accepted by all networks.
• It is not allowed to mix mapping commands Map_ADI_Read/Write_Area and Map_ADI_Read/Write_Ext_Area
within one area (Read/Write).
• It is recommended to only map one item for each mapping command during initial development, since data
area offset is only given for the first mapping item, and all mapping items may be rejected using one single
error code.
• All mapped elements, except those of types BIT1-BIT7 and PADx, must be byte aligned.
• The only implicit padding done is from the very last mapped item up to byte alignment, since the process data
needs to be of byte size when the setup is complete.
• Explicit padding is done either through available ADI elements of PADx type, or through the imaginary ADI 0,
which is assumed to be an array with 255 elements of type PAD1. Explicit padding of process data is the only
correct use of ADI 0. Padding bits might not be visible on the network.
• This command may permanently alter the state of the Anybus CompactCom 40 PROFINET IRT even though
the command is returned with an error. Network specific restrictions may lead to n mapping items to be
accepted, but with an error on mapping item n+1. If so, the mappings up to and including n will be accepted,
but all other mapping items, starting with n+1, are rejected. The number of accepted mappings is declared in
CmdExt[ 0 ] of the answer.
• Certain Anybus implementations allow the network to remap the Process Data during runtime. (Consult
the general Anybus CompactCom 40 Software Design Guide, Application Data Object (FEh) for further
information.)
See also...
Anybus CompactCom 40 Software Design Guide, Application Object (FFh)
IMPORTANT
Error control is only performed on the command parameters. The Anybus module does not verify
the correctness of these parameters by a read of the actual ADI attributes.
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Network Object (03h)
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