Rockwell Automation 1746-NI8 SLC 500 Analog Input Modules User Manual - Manual (Page 52)

5–11 Channel Configuration, Data, and Status
Publication 1746Ć6.8 - April 1997
If the module is in Class 3 mode, there are an additional 8 input
image words available for status information. The channel status
word is a part of the module’s input image. Input words 8–15
correspond to and contain the configuration status of channels 0–7.
You can use the data provided in the status word to determine if the
input configuration data for any channel is valid per your
configuration in O:e.0 through O:e.7.
For example, whenever a channel is disabled (O:e.x/11 = 0), its
corresponding status word shows all zeros. This condition tells you
that input data contained in the data word for that channel is not
valid and should be ignored.
1746ĆNI8 Module Input Image - Status Word
Class 1 Class 3
I:e.8 channel 0 status word bit mapped field •
I:e.9 channel 1 status word bit mapped field •
I:e.10 channel 2 status word bit mapped field •
I:e.11 channel 3 status word bit mapped field •
I:e.12 channel 4 status word bit mapped field •
I:e.13 channel 5 status word bit mapped field •
I:e.14 channel 6 status word bit mapped field •
I:e.15 channel 7 status word bit mapped field •
The channel status word can be analyzed bit by bit. In addition to
providing information about an enabled or disabled channel, each
bit’s status (0 or 1) tells you how the input data from the voltage or
current analog sensor connected to a specific channel will be
translated for your application. The bit status also informs you of any
error condition and can tell you what type of error occurred.
A bit-by-bit examination of the status word is provided in the chart
on the following page.
Channel Status Checking