IC-Module for EtherNet/IP
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2.10 Extended (Bit)Mapping
In this menu you will find information about the current settings of the
extended Data Broker. You can configure the individual values in the
corresponding submenus.
The Extended Mapping is executed after the general Mapping. You
can combine both mapping functions by copying the larger areas with
the standard mapping and change individual bits with the extended
mapping afterwards.
You can define a total of 16 mappings. A mapping can be up to 1024
bits long.
You must store the following information for each mapping:
– Address of the source register
– Bit position within the source register
– Address of the target register
– Bit position within the target register
– Number of bits to be copied
Info!:
– Bitwise copying requires performance.
The module works cyclically. During each cycle, the different interfaces
are operated in series and the data from the Data Broker is distributed
between the input and output data areas. Since all interfaces process
the data traffic independently of each other (asynchronous) and store
the data produced or used in a buffer, they are independent of the
module's cycle. In the case of very fast interfaces and a long cycle time,
it is possible, however, that the Data Broker does not distribute all
incoming data completely if several data packets arrive at the interface
within a cycle. Conversely, it may happen in the case of slow interfaces
that the 2nd cycle will already proceed and the output values of an
interface will be changed by the Data Broker before the values from the
first cycle have been transmitted via the interface.
For this reason, the cycle times of the module can be relevant. These
are normally less than 1 ms. Individual cycles, however, can also last
more than 5 ms. If you use the Extended Mapping very extensively, the
cycle times can increase considerably.
– Therefore, only use it if necessary.
– Only use it for small areas.
– Bear in mind:
– Mappings are processed sequentially. If target areas overlap, this
can cause problems.
– In the extended data broker no default data can be set, which should
be used in the case of a failure of a data source.
CDI
