Sensaphone SCADA 3000 Users manual - Manual (Page 173)

15-17
Chapter 15: Ladder Logic Programming
Valid Sources Valid Destinations
Inputs Outputs
Outputs
Ladder variables
Timers (preset & value) C Variables
Counters (preset & value)
Ladder variables
C variables
Diagnostics
Alarms
LADDeR LOGIC PROGRAm DeVeLOPmeNT
The SCADA 3000 Ladder Logic editor allows you to build, save, and load complex ladder
programs for use with the SCADA 3000 main unit and expansion modules. The ladder program
can run by itself or in combination with the C-Program. Specifications of the Ladder Program
include:
• 32K of Program memory (about 1000 instructions)
• 64 Timers
• 64 Counters
• 128 Floating Point variables
• 4096 bit variables
Note: Remember that Bit variables are stored as part of a 16 bit word. There are
256 words.
The real-time status of Timers, Counters, Bits and Variables can be viewed and changed on the
C and Ladder Variables form (Programming>Variables).
The unit will support up to 32K of compiled code. Note that the unit does not allow you to
retrieve the ladder program from the unit - you must save a copy of the program on your com-
puter. It is highly recommended that you make a backup copy of your ladder program.
STARTING A NeW LADDeR PROGRAm
To run the Ladder Editor, click on Control, then Ladder Editor from the Control Center menu
bar, or click on the Ladder button from the Control Center toolbar. To edit a program using
Input and Output descriptions from a specific SCADA unit, select the OnLine Program Mode
and choose a unit from the list. Click OK. This will allow the program to intelligently allow
you to select data points and check for invalid I/O addresses based on the programming in the
selected unit.
Figure 1: Ladder Program Mode