Allen-Bradley SLC 500 DeviceNet, User Manual, Page: 101 / 139

1 Publication 1747-6.5.5 - August 2000
Appendix
A
Data Map Example
What This Appendix
Contains
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.
Example Input 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
•
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
For information about See page
Example Input Mapping Scheme A-1
Example Characteristics A-1
Example Framework A-2
Example Output Mapping Scheme A-4
Example Characteristics A-4
Example Framework A-4