Honeywell 900U02-0100 - Table 24 - Controller Operating Modes

Revision 10 ControlEdge HC900 Process & Safety Controller User and Installation Manual 171
May 2019
OFFLINE Mode
The OFFLINE Mode can be entered only from the RUN Mode, and is intended primarily for performing
AI calibration.
CAUTION
Because Function Blocks are not processed and outputs are Frozen in this mode,
inputs (that is, process values) can vary from the values that existed when the
OFFLINE Mode was entered.
In Controllers with firmware earlier than V 6.0, the controller will resume program
execution with current available data when controller returns to RUN mode.
In Controllers with firmware version 6.0 or greater, the controller’s memory will get
re-initialized, outputs will be de-energized and the controller will restart when
changing from Offline to Run mode.
Before entering the OFFLINE Mode:
 KNOW all potential consequences of suspending control action.
 PLAN for all operator actions required to preclude adverse consequences while processing
is suspended, and when resuming control processing.
 EXECUTE prudent control actions (such as placing all control loop in the Manual Mode).
Failure to comply with these instructions may result in product damage.
Table 24 – Controller Operating Modes
Mode Name
Functions in selected mode
RUN
I/O scanning (Controller and Expander Racks)
Function block execution; outputs are set according to function block algorithms.
Monitoring of Diagnostics (controller rack and I/O expander racks)
Detection of I/O Modules
Other functions permitted:
 Downloading of configurations
 Indications of Forces at Status LEDs on I/O modules
Other functions NOT permitted:
 AI calibration
 AO calibration
PROGRAM
I/O scanning (Controller and expansion Racks is performed, but function blocks are
not executed, and all outputs (digital and analog) are set to OFF. (See Note 1.)
Monitoring of Diagnostics (Controller and Expander Racks)
Detection of I/O Modules
Other functions permitted:
 AI calibration
 AO calibration
 Downloading of configurations
 Downloading controller firmware (Program Locked or Program)
Other functions NOT permitted:
 Indications of Forces at Status LEDs at I/O modules