Electrex X3M, Руководство пользователя

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10.1.5 Homogenous files
Homogenous files always contain a single
“variable definition structure”
allocated in the header and
contiguous to the
“record definition structure”
. All the descriptors contained in this structure define a
variable that can be allocated either in the file header (in the descriptor) or in the data area. The area
where the variable is allocated is described by the status of the
external allocation flag
contained in the
descriptor.
Data record all share the same structure and contain only the variables specified by the descriptor list
contained in the header.
Variables allocated in the data area are distinguished in single and multiple allocation variables.
If no single external allocation descriptor is present, the data area is organized as follows:
−
File growth is unlimited (except for possible limitations imposed to the service type and for the
overall limit of 10,000 records established by the Modbus standard);
−
Each data record stores all variables defined by external multiple allocation descriptors, in the
same order in which the descriptors appear in the variable definition structure;