Allen-Bradley ControlNet PLC-5 User Manual page 90

4-8 Programming Your ControlNet System
IDO
IMMEDIATE DATA OUTPUT
Data file offset
Length
Source N12:175
1785-UM022B-EN-P - February 2002
An IDO is initiated that updates the private memory output buffer
from the source file before the next normal output-image update. The
Data File Offset (175) is the offset into the buffer where the data is
stored. The Length (24) identifies the number of words in the transfer
or a logical address that specifies the number of words to be
transferred. The Source (N12:175) is the source of the words to be
transferred. The Source should be the matching data table address in
the DOF except when you use the instruction to ensure data-block
integrity in the case of Selectable Timed Interrupts (STIs). See page
4-9.
175
24
N12:0
N12:175
For more detailed information about writing ladder programs and
programming ControlNet I/O transfers using Immediate Input (IIN)
and Immediate Output (IOT) instructions, see your programming
software documentation.
Data Table
175
IDO instruction
copies from the
data table to the
private
DOF buffer
Private DOF Buffer
0
Outputs transmitted
to the ControlNet
network on next
opportunity