User manual
Publication 1797-6.5.1 - April 1999
1-2 About the FLEX Ex Analog Modules
How FLEX Ex Analog Modules
Communicate with
Programmable Controllers
FLEX Ex analog I/O modules provide best utility when used with
ControlNet Ex products on the ControlNet network. Data connections are
established between the I/O module and an Allen-Bradley programmable
controller to transfer information between the two at a scheduled rate.
Input module information is then automatically made available in the PLC
data table through the data connection. Reciprocally, output data
information determined by the PLC program is also automatically
transferred from the PLC data table to the output module through the data
connection.
In addition, when the data connection is originally established,
configuration information for the module is automatically transferred to it
via the network.
Events following Power-Up
You must apply intrinsically safe +/-V power to your FLEX Ex analog I/O
modules. The following sequence of events occurs after power has initially
been applied to your module:
1. The module begins an interal diagnostic check. The channel 0 LED
indicator turns ON to indicate the check has begun. The indicator turns
OFF when the check is finished.
2. After the diagnostic check, module configuration information, selected
by the user and downloaded over the network, is applied by the module.
)RUPRUHLQIRUPDWLRQRQFRQILJXUDWLRQRSWLRQVVHH&KDSWHU
3. Following the module configuration download for the 1797-IE8
module, the module begins producing runtime data for the PLC.
)ROORZLQJWKHPRGXOHFRQILJXUDWLRQGRZQORDGIRUWKH2(
PRGXOHWKHPRGXOHDSSOLHVFRQILJXUDWLRQGDWDWRRXWSXWFKDQQHOV
4. If any diagnostics or alarms are generated during normal module
operation, the data is returned to the PLC.