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CWRITEREG: Continuous register writing
Function mode
Function mode
of CWRITEREG
blocks
Although an unlimited number of CWRITEREG function blocks can be programmed,
only four write operations may be active at the same time. It makes no difference
whether these operations are performed using this function block or others (e.g.,
MBP_MSTR, MSTR, WRITEREG). All function blocks use one data transaction path
and require multiple cycles to complete a job.
If several CWRITEREG function blocks are used within an application, they must at
least differ in the values of their NO_REG or REG_WRITE parameters.
The complete routing information must be separated into two parts:
l into the NODEADDR of the destination node (regardless of whether it is located
in the local segment or in another segment) and
l the routing path, in case there is a link via network bridges.
The destination address arising from this is made from these two items of
information.
The routing path is a DINT data type, which is interpreted as a sequence of two-digit
information units. Appended "00" are not required (e.g. both routing paths 4711 and
47110000 are valid, for NODEADDR 34 the result is destination reference
47.11.34.00.00).
Note: This function block puts a heavy load on the network. The network load must
therefore be carefully monitored. If the network load is too high, the program logic
should be reorganized to work with the WRITEREG function block, which is a
variant of this function block that does not operate in continuous mode, but is
command driven.
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840 USE 504 00 October 2002