Rockwell Automation 1769-XXXX Compact I/O Modules - Manual (Page 61)

Rockwell Automation Publication 1769-IN088A-EN-P - February 2011 61
I/O Memory Mapping Chapter 3
1769-IF4XOF2 The following I/O memory mapping lets you configure the 1769-IF4XOF2
module.
Input Data File
The input data file provides access to input data for use in the control program,
over-range indication for the input and output channels, and output data
feedback as described below.
The bits are defined as follows:
• SGN = Sign bit in two’s complement format. Always positive (equal to
zero) for the 1769-IF4XOF2 module.
• Ix = Over-range flag bits for input channels 0 through 3. These bits can be
used in the control program for error detection. When set to 1, the bits
signal that the input signal is outside the normal operating range. However,
the module continues to convert analog data to the maximum full-range
value. When the over-range condition is cleared, the bits automatically
reset (0).
Wo
rd
Bit Position
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0 SGN Analog Input Data Channel 0 0 0 0 0 0 0 0
1 SGN Analog Input Data Channel 1 0 0 0 0 0 0 0
2 SGN Analog Input Data Channel 2 0 0 0 0 0 0 0
3 SGN Analog Input Data Channel 3 0 0 0 0 0 0 0
4 Not Used (1)
(1) All unused bits are set to 0 by the module.
I3 I2 I1 I0
5 Not
Used H0 Not
Used H1 Not Used () E1 E0 O1 O0
6 SGN Output Data Echo/Loopback for Output Channel 0 0 0 0 0 0 0 0
7 SGN Output Data Echo/Loopback for Output Channel 1 0 0 0 0 0 0 0
IMPORTANT Input words 6 and 7 contain the output data echo/loopback information
for output channels 0 and 1 respectively. Bits 0 through 6 and Bit 15 of
words 6 and 7 should always be set to zero in your control program. If
they are not set to 0, the invalid data flag (Ex) will be set for that channel
by the module. However, the channel will continue to operate with the
previously converted value.