What This Appendix Contains; Example Input Mapping Scheme - Allen-Bradley DeviceNet 1747-SDN User Manual

What This Appendix
Contains
Example Input Mapping
Scheme
115
Data Map Example
This appendix illustrates a basic mapping example that connects a
DeviceNet network to 62 simple sensor-type devices. Each device
sends one data byte that contains one data bit and one status bit.
These are given in response to a strobe message.
Topic

Example Input Mapping Scheme

Example Output Mapping Scheme
This example's input mapping scheme is a simplified and fixed map
of discrete input data and status bits for DeviceNet devices. It is
mapped to discrete inputs and the device input data table.
Example Characteristics
This example has the following characteristics:
• Strobe is used to query DeviceNet devices.
• Poll is disabled.
• The input data bit is fixed and occupies the lowest-order bit in
the lowest-order byte of the strobe (bit #1).
• One bit of status data is accepted from each node responding to
the strobe.
• The status data bit is fixed and occupies the next lowest-order
bit in the next lowest-order byte (after the input data bit) of the
strobe (bit #2).
• Input and status data bits accepted from each node are mapped
to the scanner's discrete-input data table.
• Input and status data bits accepted from each node are fixed and
predefined.
Appendix
Page
115
118
Publication 1747-UM655B-EN-P - June 2007
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