Rockwell Automation 2711-ND3 PanelBuilder v2.60 Software User Manual - Manual (Page 65)

4–9 Communications Overview
Publication 2711-6.0
Discrete I/O addresses communicate directly with the controller and
provide faster updates than block transfers. Discrete I/O is
recommended for:
•
Push buttons (for rapid response times)
•
Any critical values that you want updated immediately
A PLC rack has 128 discrete I/O points (8 input words/8 output
words). If additional rack space is needed for an application, use
block transfers.
You must assign a read or display tag to an output address. If you
assign a read tag to an input address, a validation error occurs. The
read and write tags must have different tag names and reference
different addresses.
Discrete I/O Addressing for 1771-SN Scanners
The I/O addressing syntax for the 1771-SN Scanner (Series A) is:
I:YYW/BB O:YYW/BB
where:
YY = Rack number
W = Word or group address
BB = Bit address, 0-7, 10-17 octal
For example:
I:024/10
addresses input bit 10, Rack 2, Module 4.
Discrete Addressing for 1747-SN Scanner, Series A and B
The addressing syntax for the 1747-SN Scanner (Series A and B) is:
I:X.WW/BB O:X.WW/BB
where:
X = Slot where 1747-SN is installed in rack
WW = Word address, 0 - 31 decimal
BB = Bit address, 0-15 decimal
For example:
I:1.7/13
addresses input bit 13 of Word 7, Slot 1 (where 1747-SN Scanner
resides).
Discrete I/O