Channel status checking, Channel status checking -13 – Rockwell Automation 1746-NT4 Series B,D17466.6.1 SLC 500 4-Channel Thermocouple/mV Input Module User Manual User Manual
Page 65
Publication 1746-UM007C-EN-P - July 2004
Channel Configuration, Data, and Status 5-13
Channel Status Checking
The channel status word is a part of the thermocouple module’s input
image. Input words 4-7 correspond to and contain the configuration
status of thermocouple channels 0, 1, 2, and 3 respectively. 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.3.
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.
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
thermocouple or millivolt 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 error
occurred.
A bit-by-bit examination of the status word is provided in the chart on
the following page.
Module Input Image (Status Word)
CH 0 Channel Status Word
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
I:e.4
I:e.5
I:e.6
I:e.7
CH 1 Channel Status Word
CH 2 Channel Status Word
CH 3 Channel Status Word