Rockwell Automation 1769-IF4XOF2 Compact 8-Bit Low Resolution Analog I/O Combination Module - Manual (Page 48)

Publication 1769-UM008A-EN-P - November 2001
4-4 1769-IF4XOF2 Module Data, Status, and Configuration Channels
Input Data Words 0 through 3
All bits shown as 0 (bits 0 through 6) are always set to 0. Bits 7
through 14 contain the 8 input data bits. The table below illustrates
the format of the input data, words 0 to 3.
Input Data Words 4 through 7
These words contain diagnostic and control information. For details
see Bit Definitions for Input Data below.
Bit Definitions for Input Data
Sign Bit (SGN)
The sign bit is always positive (equal to zero).
Over Input Range Flag Bits (I0 to I3)
Word 4, bits 0 to 3 (i0 to I3) contain over-range flag bits for input
channels 0 through 3 respectively. 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 to (0).
Over Output Range Flag Bits (O0 and O1)
Word 5, bits 0 and 1 (O0 and O1) provide over-range indication for
output channels 0 and 1. These bits can be used in the control
program for error detection. When set to 1, the bits signal that the
output 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 to 0.
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
SGN A7 A6 A5 A4 A3 A2 A1 A0 0 0 0 0 0 0 0
TIP
Under-range indication is not provided for the
1769-IF4OXF2 because zero is a valid number.
Refer to Table 4.9 Valid Input Data on page 4-14 to
view the normal operating and over-range areas.