EET3370 – Programmable Logic
Controller Basics
Lab 5 –
SLC-500 Timer Lab
Purpose
The purpose of
lab 2 is to introduce you to the timing functions available in the SLC500. In this lab you will program each of a series
of timing circuits in the SLC500 and demonstrate it with the SLC500 I/O panel.
Applicability
Criteria:
The functions in
this lab allow you to program common timing functions used for both delay-on
and delay-off instructions. Understanding
these timing functions will enable you to build complex control such as
time-driven sequencing circuits, shift register clock circuits, and wave form
generation circuits.
Procedure:
You need to create a file called timerxx before you can run this lab. Refer to first SLC 500 lab hand out if you have forgotten how to do this.
1. Enter the following program.
I:1
|----]
[-------------------------------+TON-----------------+ |
|
0
|Timer On Delay +-(EN)-|
|
|Timer T4:0 +
|
| |Time
base 0.01 +-(DN) |
|
|Preset 300 |
|
| |Accum
0 | |
| +--------------------+ |
| T4:0 O:2/0 |
|----]
[---------------------------------------------------( )---|
DN
Make sure your interface panel power is off. Connect a switch to the input module in slot 1, terminal 0. Connect a light to the output module in slot 2, terminal 0. Turn on the power, download and monitor your program. Run the program. Turn on the switch, and count the time before the light energizes. It should be 3 seconds.
The
circuit above is commonly referred to as a delay-on timer. The output energizes after a time delay when
the switch is closed.
2. In the space below, draw a ladder diagram
where the output energizes instantly when the switch is thrown, and when the
switch is turned off, it will delay 3 seconds before going off.
Use input
I:1/1, output O:2/1, and timer T4:2
Enter
your diagram into the computer. Add the
rungs to the end of the program that already exists. Download the program, and run the
program. Monitor your timer. When you have this working have the instructor initial your control.
3. Program the following ladder logic into the computer. Use input I:1/2,
output 0:2/2, internal coil B3:1/0, and timers T4:2 & T4:3.
I:1 B3:1
|----] [----]/[-------------------+TON-----------------+ |
| 2
0 +Timer On
Delay +-(EN)-|
| |Timer T4:2
+ |
| |Time
base 0.01 +-(DN) |
| |Preset 500
| |
| |Accum 0
| |
|
+--------------------+ |
| T4:2 0:2 |
|----]
[---------------------------------------( )------------|
| DN 2 |
|
|
| T4:2
|
|----]
[--------------------------+TON-----------------+ |
| DN +Timer On Delay +-(EN)-|
| |Timer T4:3 +
|
| |Time
base 0.01 +-(DN) |
| |Preset 50
+ |
| |Accum 0
+ |
|
+--------------------+ |
|
|
| |
| T4:3
B3:1 |
|----]
[----------------------------------------( )-----------|
| DN 0 |
Note:
B3:1/0 is an example of programming an internal output instruction that doesn't
use up a terminal on an output module.
Run the
program, and describe in detail how the timers control output O:2/2.
____________________________________________________________
____________________________________________________________
____________________________________________________________
____________________________________________________________
4. In the space below, draw a ladder diagram that
will cause O:2/3 and O:2/4 to alternate on at a 0.5
second rate. This process should
continue repeatedly until input 3 is turned off. Use input I:1/3,
timers T4:4 and T4:5, and outputs O:2/3 and O:2/4.
Verify
the operation of this circuit. When you
have this working have the instructor initial your
control.
DELETE ALL THE FILES YOU CREATED
WHEN YOU ARE FINISHED WITH THIS LAB.