Sensaphone SCADA 3000 Users manual - Manual (Page 177)

15-21
Chapter 15: Ladder Logic Programming
To delete instructions, click on the Instruction and click the Delete button from the toolbar; or
right-click on the instruction and choose Delete from the menu.
Syntax Checking
You can check your program for instruction and address errors by selecting the Syntax Check
button from the toolbar, or by clicking Program>Syntax Check from the main menu. If any
errors are found, the instruction with the error will be highlighted in red. The syntax checker
will locate errors one at a time. Continue running the syntax check program until all errors are
eliminated. Syntax check status will be displayed on the lower righthand side of the screen.
Compiling, Verifying and Uploading
The ladder program must be compiled before it can be uploaded to the SCADA 3000. The
unit will support up to 32K of compiled code. Compiling translates the graphical instructions
into a sequential file that can be read by the SCADA 3000. In addition, the program will be
checked for missing or incomplete addresses and illegal logic. If any errors are detected they
will be listed on the screen. Once you correct the errors be sure to re-compile the program
before uploading it. To Compile the program click on Program, then Compile and Upload, or
click on the Compile and Upload button from the toolbar. Once your program compiles without
errors, you can upload it by clicking the Yes button at the prompt.
Running and Stopping Ladder execution
The ladder program is controlled by the Ladder and C-Program Start/Stop form located on
the SCADA 3000 Main Programming form. This is accessed by clicking the Start/Stop button
on the Main Programming toolbar, or by selecting Programming, then Control from the main
menu.
Figure 6: Start/Stop form
The Ladder and C-Program Start/Stop screen provides information, timing measurements
and options. At the top of the screen is an option which determines how the outputs (relay &
analog) are treated when the Control Switch is placed in the Disable position. If the option
is not set, then the outputs will remain in the state they were in when the switch is placed in
the Disable position. When the option is set, all unforced relay outputs will be switched OFF
and all analog outputs will be set to their low table value. Forced outputs are unaffected by the
position of the control switch. To enable this option, click in the option box at the top of the
screen.
The Start/Stop form also indicates: if control programs are running or stopped; if valid Ladder
or C-Programs are loaded; if control programs are enabled or disabled. It also provides control
program timing information. The timing statistics are described below.
Duration: Amount of time for the Ladder or C-Program to execute.
Scan Time: Amount of time for the inputs to be read, plus the duration of the