Today I worked on a quick digital logic test to get an introduction to the Crouzet Slim Programmable Logic Controller and by extension its Crouzet Soft program. Working on this mini project reminded me of several important aspects of building logic, but one thing was especially important: how much organization improves overall clarity.
Objectives
The project itself was simple. I was given two push buttons and a combination red/green panel lamp PCL2224V150B. The goal was to control a light with four possible states:
- State 0 - Off
- State 1 - Red
- State 2 - Green
- State 3 - Blinking Red/Green
These states are controlled by two push buttons, where each input button turns on a specific color when pressed and triggers the lamp to alternate between colors when both buttons are pressed.
Figure 1: Workbench Setup
Initial Unorganized Program
After working on it for an hour, I ran into some issues straight away due to the multitude of wires making the logic look more confusing than it actually was. Having all the wires overlapping can make it confusing to immediately know which logic blocks correspond to each state. This led me to try and separate the logic blocks apart to try and get the wires more separated, but at first glance this setup was still hard to explain and debug. At this point, I used Crouzet Soft’s Text option to label connections instead of showing each one as a physical line in the circuitry.
Figure 2: Original Logic Circuit
Revised Program
Figure 2 shows the organized Logic circuitry while testing State 3 in the debugging mode in Crouzet Soft. Getting rid of the wires and opting for text labels instead allows the user to properly organize their logic blocks into sections and quickly know from a glance the inputs and outputs of each block. It also does not interfere with debugging as the program is still able to indicate which elements are on or off without the wires present. Having the wires shown on the circuit as organized above would result in an entire sea of crossed wires, but using the Text feature is an easy way to prevent this from happening while still being able to organize your logic blocks. It improves clarity not only while building the circuit but could also make the circuitry easier to explain to others.
Figure 3: Organized Logic Circuit