Rockwell Automation 1769-IF4XOF2 Compact Combination Analog Module - Manual (Page 15)

Compact™ Combination Analog I/O Module 15
Publication 1769-IN057A-EN-P - July 2001
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).
•
Ox = Word 5, bits 0 and 1 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 (0).
•
Ex = When set (1), this bit indicates that invalid data (e.g. the value sent by
the controller is outside the standard output range or increment; e.g. 128,
256, etc.) has been set in the output data bits 0 through 6, or the sign bit
(15).
•
Hx = Hold Last State bits. When set (1), these bits indicate that the channel
is in a Hold Last State condition.
•
Words 6 and 7 = These words reflect the analog output data echo of the
analog value being converted by the digital/analog converter, not necessarily
the electrical state of the output terminals. They do not reflect shorted or
open outputs.
TIP
Under-range indication is not provided because zero
is a valid number.
IMPORTANT
It is only important to use the loopback function of input
words 6 and 7 if the controller supports the Program
Mode or Fault Mode functions, and if it is configured to
use them.