Rockwell Automation DEVICENET 1771-SDN, User Manual

Page: 125 / 139

Publication 1771-6.5.132 - June 2000
Data Map Example D-3
Input Data Table Formats
The manner in which bits are mapped to the input data table depends
on the address density used. The following example is a 2-slot
configuration. Note that discrete mapping is not possible in 2-slot mode.
node #1 1 byte
S D
node #2 1 byte
S D
node #1 1 byte
S D
node #2 1 byte
S D
Channel A
Channel B
to node #62
to node #62
Module Status
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
15 0
2D 1D
79
95
143
159
206
222
270
81 80
2D 1D
145 144
2S 1S
208 207
2S 1S
Input Data Bits from Channel A Devices
bits 16-79
bits 80-143
Input Data Bits from Channel B Devices
bits 144-206
Status Bits from Channel A Devices
Status Bits from Channel B Devices
bits 207-270
word 0
word 1
word 2
word 3
word 4
word 5
word 6
word 7
word 8
word 9
word 10
word 11
word 12
word 13
word 14
word 15
word 16
Bit numbering in the data table is right
to left, beginning with zero. Note: 1 word = 2 bytes
1 byte = 8 bits
Each device’s status and data bits are mapped into
the device input data table. Data bits from devices
on channel A are mapped into the first four words
after the module status word in ascending,
numeric order according to the device’s node
address. For example, node #1 is mapped then
node #2, #3, #4, and so on.
Input data bits from channel B as well as status
bits from channels A and B are mapped into
similar four-word groups. These bits are also
ordered by node address in ascending numeric
order.
Device Input
208 207
2S 1S
Note:
D = data bit
S = status bit
1D & 1S = data and
status bits for node #1
2D & 2S = data and
status bits for node #2