Rockwell Automation 1794-OF8IH FLEX Isolated Input/Output HART Analog Modules - Manual (Page 25)

Publication 1794-UM065B-EN-E - September 2010
Configurable FLEX I/O Analog Module Features 13
Fault Alarm
Fault Alarm selects whether the channel fault detection is enabled or disabled.
There is a 100 Hz (10 ms) filter for wire off or lead break detection.
Use your programming software to set the Fault Alarm. Set the feature bit to 0
to disable the alarm. Set the bit to 1 to enable wire off/lead break fault
detection.
Understand Image Table
Mapping and Bit/Word
Descriptions All Allen Bradley FLEX I/O modules have a sixteen word table of Real Time
Data (RTD) to be transferred between the controller and the I/O module.
4 mA as
4…20 mA 0.1% of
4…20 mA 2…22 mA 2000…22000
(2.000…22.000 mA) 1000/
1.0 µA Min=2 mA
Max=22 mA
hold
Last=hold
FS value
5 4…20 mA — 4…20 mA Not assigned
6 4…20 mA 4…20 mA Not assigned
7 Unsigned
integer as
4…20 mA 0.03% of
4…20 mA 4…20 mA 0…65535
(4…20 mA) 4095/
0.244 µA Min=4 mA
Max=20 mA
hold
Last=hold
FS value
8 0…20 mA 0…20 mA Not assigned
9 0…20 mA 0…20 mA Not assigned
10 0…20 mA 0…20 mA Not assigned
11 0…20 mA 0…20 mA Not assigned
12 4…20 mA Not assigned
13 4…20 mA Not assigned
14 % as
4…20 mA 0.16% of
4…20 mA 2…22 mA -1250 … +11250
(2’s complement)
(-12.50% …
+112.50%) 625/
1.6 µA Min=2 mA
Max=22 mA
hold
Last=hold
FS value
15 4…20 mA 4…20 mA Not assigned
1794-OF8IH Data Formats
Data
Format Format Resolution Full
Output
Range
Module Data Processing Data Table Value
(Interpretation) Count per
mA/
Resolution Analog Fault
State
Output =
datatable (
1000
)
Output = 16
datatable (
65535
)
+ 4
Output = 16
datatable (
10000
)
+ 4