WI-GTWY-9-xxx Wireless Gateway V1.18
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For example Modbus/TCP areas start from location 1, but other fieldbuses may start at location
0.
Note:
•
The Fieldbus Interface IN
and
OUT Area both number from 0 - that is, there is an input 0 as
well as an output 0 (an offset may apply for some protocols).
•
All IN/OUT Area locations accessed by the fieldbus must be part of a fieldbus mapping in the
WI-GTWY-9-xxx - that is, if a host device is writing to bytes 0 – 100 in the OUT Area,
there must be at least one fieldbus read mapping that uses these locations - if not, the
Fieldbus Interface will generate an error response message.
•
Fieldbus mappings to/from the IN/OUT areas should always start at location 0 if possible (or
the lowest available unused location). Configuration Software will always automatically
choose the next lowest available location – it is strongly recommended that this topology be
used so as not to place unnecessary processing overhead on the module.
4.9.5
Fieldbus Mapping Configuration
The example below shows the Fieldbus Mapping
configuration screen when adding new or editing existing Fieldbus Mappings. Starting
from the left of the screen, the I/O Register selection specifies the starting I/O Register
from the Radio Interface (press the “…” button to make a selection graphically). The I/O
Count parameter specifies how many consecutive I/O Registers are to be transferred or
linked
. Command Type and Transfer Mode specify the type of Fieldbus Mapping (see
Fieldbus Mappings table above). Finally, I/O Location specifies the IN or OUT Area
location in the Fieldbus Interface (see earlier diagram).