Specifications

Publication 1794-SG002D-EN-P - May 2012
Select FLEX Ex I/O Modules 91
Analog Modules
Choose analog I/O modules when you need:
• Configurable channels allow the module to be used with a variety of
sensors.
• On-board scaling eliminates the need to scale the data in the controller.
Controller processing time and power are preserved for more important
tasks, such as I/O control, communications, or other user-driven
functions.
• On-line configuration. Modules can be configured in RUN mode using
the programming software or the control program. This allows you to
change configuration while the system is operating. For example, the input
filter for a particular channel could be changed, or a channel could be
disabled based on a batch condition.
• Over- and under-range detections and indications eliminates the need
to test values in the control program, saving valuable processing power of
the controller. In addition, since alarms are handled by the module, the
response is faster and only a single bit needs to be monitored to determine
if an error condition has occurred.
• Ability to direct output device operation during an abnormal
condition. Each channel of the output module can be individually
configured to hold its last value or assume a user-defined value on either a
run-to-program or run-to-fault condition. This feature allows you to set
the condition of your analog devices, and therefore your control process,
which may help to ensure a reliable shutdown.
• Selectable input filters allows you to select from several different filter
frequencies for each channel that best meets the performance needs of
your application based on environmental limitations. Lower filter settings
provide greater noise rejection and resolution. Higher filter settings
provide faster performance.
• Selectable response to broken input sensor. This feature provides
feedback to the controller that a field device is not connected or operating
properly. This allows you to specify corrective action based on the bit or
channel condition.
Analog I/O Module Summary
Catalog Number Inputs Outputs Terminal Base Unit Signal Range Module Type
Input Modules
1797-IE8 8 — 1797-TB3, 1797-TB3S 0…20 mA 16-bit single-ended,
nonisolated inputs
1797-IE8H 16-bit single-ended,
nonisolated inputs with
HART capability
1797-IE8NF 16-bit single-ended,
nonisolated inputs with
noise filter
1797-IRT8 0…500 Ω
-40…100 mV
TC
RTD
16-bit, nonisolated RTD
thermocouple/mV inputs