Rockwell Automation 1785-Lx0C15 ControlNet PLC-5 Programmable Controllers User Manual - Manual (Page 87)

1785-UM022C-EN-P - February 2008
4-7
In the previous example, an IDI is initiated that updates the
destination file from the private buffer before the next normal
input-image update. The Data File Offset (232) is the offset into the
buffer where the data is stored. The Length (10) identifies the number
of words in the transfer—it can be an immediate value ranging from 1
to 64 or a logical address that specifies the number of words to be
transferred. The Destination (N11:232) is the destination of the words
to be transferred. The Destination should be the matching data table
address in the DIF except when you use the instruction to ensure
data-block integrity in the case of Selectable Timed Interrupts (STIs).
See Using Selectable Timed Interrupts with a Program
on a ControlNet Network on page 4-9.
IDI
IMMEDIATE DATA INPUT
Data file offset
Length
Destination
IDI copies from
the private DIF
buffer to the
data table Inputs arrive from
the ControlNet
network
N11:232 232
N11:0 0
Data Table Private DIF Buffer
232
10
N11:232