Honeywell UMC800 - Manual (Page 63)

Operation
Operational Modes and Controls
Release F UMC800 Controller Installation and User Guide 55
4/01
Table 15 Controller mode switch summary
Controller Mode Manual
Switch setting
Mode Control
through the Configuration Port or Operator Interface
RUN Unrestricted mode changes.
The mode selected via the Configuration port or operator interface
overrides the controller manual mode switch position.
OFFLINE Can override OFFLINE mode to set controller to PROGRAM mode.
PROGRAM No mode changes can be made.
Setting mode switch to PROGRAM and then to RUN
Setting the controller mode switch to PROGRAM and then to RUN forces the controller to perform a cold
start and other actions depending upon the condition of the database RAM.
When the mode switch is
changed from PROGRAM to RUN, the controller verifies that a valid database configuration is present in
RAM before starting control loops.
So that,
If . . . (Condition of RAM) Then . . . (Controller Action)
A valid database configuration is present in RAM, Configuration is written to flash PROM. (User-
defined variables are initialized to zero.)
Database configuration in RAM is found to be bad,
but the configuration in flash PROM is good, RAM is restored from the flash PROM that
contains the configuration values from the last
cold start.
[See CAUTION in Power Up / Power Down
(page 52).]
If the database configuration is found to be bad in
both RAM and flash PROM, Controller is set to a null default configuration.
A system diagnostic INVALID CONFIG. is
generated.
In all cases the controller performs a cold start when the controller mode is set to PROGRAM and then to
RUN regardless of what method is used to change the mode.
Whether the mode was set through the
Configuration port or the operator interface, this action causes the PROGRAM mode to be cleared.
Additionally, setting the mode switch to PROGRAM and then RUN allows you to change the controller
mode if communications were disconnected to the Configuration port or operator interface while the
controller was still in PROGRAM mode.