Rockwell Automation 1756-XXXX ControlLogix Analog I/O Modules - Manual (Page 46)

46 Publication 1756-UM009C-EN-P - December 2010
Chapter 3 ControlLogix Analog I/O Module Features
Sensor Offset
You can add this offset directly to the input or output during calibration
calculation. The purpose of this feature is to let you compensate for any sensor
offset errors which may exist, such offset errors are common in thermocouple
sensors.
To set a sensor offset, see page 210 in Chapter 10 .
Latching of Alarms
The latching feature allows analog I/O modules to latch an alarm in the set
position once it has been triggered, even if the condition causing the alarm to
occur disappears.
Data Format
During initial configuration of any ControlLogix analog I/O module, you
must choose a Communication Format. The format determines the data
format of data exchanged between the owner-controller and the I/O module.
For example, if you use an integer data format with the 1756-OF6CI module,
the clamping feature is not available for use.
Format type Description
Integer This mode uses a 16-bit signed format and allows faster
sampling rates while using less memory in the controller but
also limits the availability of features on your module.
The faster sampling rates and lower memory usage vary
according to module and application type. For more
information on the specific sampling rates, see the Module
Filter section in the module-specific chapters. Memory
usage can be up to 50% less than in floating point.
Floating point This mode uses a 32-bit IEEE floating point format and offers
all module features.
TIP
We recommend that you use the floating point data format in
most applications. Floating point is simpler to use. All
ControlLogix analog I/O modules default to floating point when
initialled configured.
You should use only the integer data format if your application
requires faster sampling rates than offered in floating point or if
your application memory is extremely limited.