Getting started
Copyright IXXAT Automation GmbH
31
IEM Manual, 1.5
2.3.5.2 Characteristics
process data size:
2 x 1536 bytes (input and output data), respectively
2 x 850 bytes if a IEM with integrated switch is used
async data size:
1024 bytes
mappable data objects:
500 elements
2.3.6 Storing/Restore configuration parameter
The IEM implements a mechanism to store respectively restore all dynamically
created mapping entries of variables in the non-volatile (flash) memory of the
module. After each power cycle the host application has the possibility to re-
store these parameters from flash or to create new mapping entries.
To store the configuration parameters inside the flash, the host application has
to create all necessary entries once and finally call the API function
. After that the module restores these parameters automat-
ically by getting the channel open command. The IEM will block all create
commands which refer to an already restored variable. At this point it’s im-
portant to know that the stored configuration will only be used, if the host
doesn’t provide a valid configuration structure. If a valid configuration structure
is written by the host application the stored configuration will always be ig-
nored.
To delete the former stored configuration the host application has to call
Note:
Please keep in mind that the restore does not affect the configura-
tion which is held in volatile memory. To activate the restored con-
figuration, the IEM has to be reset.
2.3.7 Configuration structure
Depending on the selected protocol, a specific configuration structure has to
be written to the acyclic area of the shared memory. This structure is different
for
each
protocol
but
has
the
common
member
structure
COM_t_
BOARD
_CONFIG
. With the help of these structures the module evalu-
ates if a stored configuration should be loaded from a non-volatile memory. If
the configuration stored in the acyclic area should be processed by the mod-
ule, the application has to set the member
dw_validFlag
to
COM_k_VALID
. In
this case potential stored objects are ignored. The application needn’t to write
the configuration structure if there is a stored configuration.
To clarify this correlation the following code snippet is used: