Rockwell Automation 1756-OF8H ControlLogix HART Analog I/O Modules - Manual (Page 154)

154 Rockwell Automation Publication 1756-UM533C-EN-P - February 2011
Chapter 10 Unlatch Alarms and Reconfigure Modules By Using Ladder Logic
Reconfigure a Module It is sometimes advantageous to change the functional operation of a module in
the ControlLogix system automatically via the user program rather than using
RSLogix 5000 software to reconfigure a module. This way, changes in the process
can dictate when the reconfiguration should take place rather than the user
performing that function manually.
Use the steps in this example when reconfiguring a module via ladder logic.
1. Move new configuration parameters to the Configuration portion of the
tag structure associated with the module.
2. Use a message instruction to send a Reconfigure Module service to the
same module.
Before the new configuration parameters are sent to the module, you must make
sure that their relationship to each other is in a format the module accepts (see
Table 47 and Table 48 ).
The tables below list module parameters that you can change via ladder logic:
IMPORTANT Reconfiguring analog modules via ladder should be limited to
functions that involve the changing of values only. We do not
recommend that enabling or disabling features be done via ladder.
Use RSLogix 5000 software to enable or disable these features.
Table 47 - Analog Input Module Parameters
Feature Restriction
High engineering value Must not be equal to low engineering value
Low engineering value Must not be equal to high engineering value
High-High alarm value Must be greater than or equal to high alarm value
High alarm value Must be greater than low alarm value
Low alarm value Must be less than high alarm value
Low-Low alarm value Must be less than or equal to low alarm value
Deadband Must be less than half of high alarm minus low alarm
Table 48 - Analog Output Module Parameters
Feature Restriction
High clamp value
(1)
(1) The values for user-defined state at Fault or Program (set during initial configuration) must fall within the range
of the High and Low Clamp values.
Must be greater than low clamp value
Low clamp value (1) Must be less than high clamp value