Rockwell Automation 1747-SCNR ControlNet Scanner Module Reference Manual - Manual (Page 125)

Publication 1747-RM623D-EN-P - June 2006
Application Examples E-47
Note that addresses in the Connection Properties window are
already displayed in the fields. To have RSNetWorx for
ControlNet software choose the next available, valid I/O or
M-file addresses for all connections:
a. Click the Auto Address Preferences button.
b. Click the box next to Enable Automatic Addressing on Insert
so that a check mark appears in the box.
c. Click OK.
The Connection Name by default is Discrete Exclusive Owner.
This is the rack connection we want. The first available I/O
addresses are I:3.1 and O:3.1, where the 1747-SCNR is in slot 3
of the processor chassis. The first available starting I/O
addresses have been placed into the Input Address and Output
Address fields by RSNetWorx for ControlNet software, because
automatic addressing was previously selected in the Auto
Address Preference screen.
Words I:3.0 and O:3.0 are reserved. Note that the input data
from the 1794-IB16 module is found in the processor’s input
image word I:3.3, the output data written to the 1794-OB16
module is from the processor’s output image word O:3.2.
IMPORTANT
There is a two-word offset for input data for rack
connections and module connections when working with
a 1794 Flex ControlNet adapter. Therefore, for this
example, the input data for the input module in slot 0 of
the remote 1794-ACNR15 system is written to I:3.3 in the
SLC processor’s input image.
The starting input address configured in RSNetWorx for
ControlNet software for this rack connection was I:3.1, but
I:3.1 and I:3.2 are used for status information. Therefore,
the actual input data begins after the two words of status
information. I:3.4 is not used in this example because an
output module resides in slot 2.
Also, note that there is no offset for the outputs in a rack
connection. O:3.2 is the output image word written to the
output module located in slot 1 of the 1794-ACNR15
chassis. In addition, this same offset scheme applies to
module connections for Flex I/O on ControlNet. For this
example, the input and output data for the 1794-IE4XOE2
is located in M1:3.5 through M1:3.8 and M0:3.3 and
M0:3.4.