34
CTI Janus Programmable Automation Controller IOG
5.
The controller data base is saved to the internal SD card when power is lost, providing an option to execute a
Hot Start
where all variables are set to their last state value.
6.
All user data files created by user logic programs will be stored on the internal SD card in the /ctiplc/user
folder. To access them externally, the user must manually transfer these files to the front panel SD card using
the F
ILE
M
ANAGEMENT
web page.
7.
When a project is downloaded from CTI Workbench while the run-time is stopped, that project is stored on
the internal SD card as the
“active” applic
ation. All project source files are downloaded with the program, and
they are also copied to the appropriate folder on the internal SD card. The previous program and source files
(if they exist) are renamed and saved. Any older versions are overwritten.
The state of the application program following download is determined by selection
for Operation following
Project Download
in C
ONFIGURATION
/G
ENERAL
S
ETTINGS
web page. The application remains in this state until user
changes the program state or the controller is reset.
8.
The controller includes a predefined
Cycle Instruction Overrun
watchdog
to prevent the user program from
excessively looping without completing a normal cycle. This watchdog uses a software timer to measure each
controller cycle and limits maximum cycle time to one (1) second.
9.
The controller firmware also includes a
System Watchdog
with preset of 6 seconds that expires only if the
controller operating system becomes inoperable. The expiration of the System Watchdog will cause the Janus
controller to reboot.
10.
If a controller execution error is detected, the event is recorded in the Event Log and controller will enter the
ERROR
state.
ERROR
state can be cleared by connecting Workbench to the controller or by resetting the
controller via web page or
C
LEAR
E
XCEPTION
button (if either is enabled).
NOTE
Logic can be added to the Exception Programs (pOnBadIndex and pOnDivZero) for special handling of
these error conditions.
If the C
LEAR
E
XCEPTION
button is enabled, it can be used to reset the controllers after critical errors.
See Section 2.6 for details.
