WI-GTWY-9-xxx Wireless Gateway V1.18
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BIT transfer, that each individual bit in the Fieldbus Interface is transferred to an entire 16-bit I/O
Register. Note also that there is a word-location 1 for both the Fieldbus OUT
and
IN areas.
The third mapping is another “Read BIT” mapping, reading 8 bits from Fieldbus OUT Area
word-location 1 to I/O Registers 4320 – 4327 (i.e. local DOT 1 – 8). Note here that we are again
reading from Fieldbus OUT Area word-location 1 (as with the previous mapping). However,
since each word-location contains 16-bits and the last mapping used only 12 of those, we have
been able to follow on from the previous mapping (see below).
The Fieldbus Register Selection screen above was shown when selecting the Fieldbus OUT Area
location for the third mapping in the above example. This screen shows the currently used
portion of the Fieldbus OUT Area, and allows the user to graphically select the location for the
current mapping. NOTE – by default configuration software will always choose the next
available Fieldbus Interface register for fieldbus mappings. Allowing configuration software to
automatically make the selection is strongly recommended wherever possible.
Clicking on the required location in the top panel will alter the currently selected word-location.
Further, clicking individual bits in the “Bit Usage” panel at the bottom of the screen, allows the
current BIT mapping to be specified at the bit-level of the currently selected word.
The lighter blue areas indicate the extent of already existing fieldbus mappings. It can be seen
that bits 0 – 11 of word location 1 have already been used (by the second mapping in the
example). The dark blue area in the register selection screen above shows the extent and location
of the current fieldbus mapping graphically. The status panel at the bottom of the window always
displays the extent of the current selection, which can be seen to be word 1, bit 12 to word 2, bit
3.
