Channel status checking, Channel status checking -12 – Rockwell Automation 1746-NT8 SLC 500 Thermocouple/mV Analog Input Module User Manual User Manual

Page 52

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Publication 1746-UM022B-EN-P - January 2005

4-12 Channel Configuration, Data, and Status

Channel Status Checking

You can use the information 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.

The channel status 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 of error occurred.

A bit-by-bit examination of the status word is provided in the chart on
the following page.

Channel 0 to 7 Status Word (I:e.0 through I:e.7) - Bit Definitions

To Select

Make these bit settings

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

Channel

Channel Disable

0

Status

Channel Enable

1

Input
Type

Thermocouple J

0

0

0

0

Thermocouple K

0

0

0

1

Thermocouple T

0

0

1

0

Thermocouple E

0

0

1

1

Thermocouple R

0

1

0

0

Thermocouple S

0

1

0

1

Thermocouple B

0

1

1

0

Thermocouple N

0

1

1

1

-50 to +50 mV

1

0

0

0

-100 to +100 mV

1

0

0

1

Invalid

1

0

1

0

Invalid

1

0

1

1

Invalid

1

1

0

0

Invalid

1

1

0

1

Invalid

1

1

1

0

CJC temperature

1

1

1

1

Data
Format

Engineering Units x 1

0

0

Engineering Units x 10

0

1

Scaled-for-PID

1

0

Proportional counts

1

1

Open Circuit

Zero on open circuit

0

0

Max. on open circuit

0

1

Min. on open circuit

1

0

Disabled

1

1

Temperature
units

°C

0

°F

1

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