Chapter 5 Operation; Controller Operation Overview - CTI Janus 2500C-J Series Installation And Operation Manual

This section describes aspects of the Janus Controller operation. Additional information may be found in the Janus
Workbench Help.

5.1 Controller Operation Overview

1. The Janus controller can have the following operational states:
•
APPLICATION STOP: Application is halted. All fieldbus protocols and logic are stopped.
•
RUN (Janus Workbench displays "RUNNING"): All facets of the application operation are active - all
configured fieldbus protocols and logic program are executing.
•
LOGIC STOP: Application is active. Logic processing is stopped and controlled via the debug "step"
operations. Fieldbus protocols are running and the data base is updated.
•
ERROR: Application is halted. All fieldbus drivers are stopped. The controller must be rebooted or
operation mode changed to Application Stop before it can return to RUN state. Alternatively, you can
use the C
LEAR
Pushbutton.
2. Janus Workbench can be used to transfer controller operation from APPLICATION STOP to RUN mode with
the following initialization states:
•
Cold Start: All variables are set to their initialization values.
•
Warm Start: RETAIN variables are set to their last values, and all other variables are set to their
initialization values.
•
Hot Start: All variables, instance data, timers, and SFC states are restored to their last values.
Warm Start and Hot Start options are not available immediately after an application is downloaded from
Janus Workbench to the controller.
3. Controller programs can be compiled for Debug or Release operation.
•
Debug: Allows remote debugging of the application program while executing on the target. This
includes use of breakpoints, trace points, cycle-to-cycle debug, and step-by-step debug operations.
•
Release: Version compiled for faster execution without support for debugging operations. Release
version will typically execute approximately 10% faster than the corresponding Debug version.
4. RETAIN variables are special designated Global variables whose latest value is saved to the internal SD card at
the end of every scan cycle. There is no limit on the number of variables you can designate as RETAIN. This
provides following user options:
•
Stored values can be used as "initialization values" for specified variables when application is started
using the Warm Start option.
•
You can save or restore values of all RETAIN variables on demand thru the use of the F_SAVERETAIN
and F_LOADRETAIN function blocks.
CTI Janus Programmable Automation Controller IOG
CHAPTER 5
E button (if enabled) to exit ERROR state. See
XCEPTION
OPERATION
Section 2.8 Clear Exception
33