Challenge Instructions
Difficulty:
Easy
PLC Software

MicroLogix 1100 Motor Starter Implementation

Create a system that will start and stop a motor using the following components:

Hardware

  • MicroLogix 1100 PLC [1763-L16BWA]
  • Motor Contactor [Ex: `00-C09A10]
  • Normally Open “Start” Push Button
  • Normally Closed “Stop” Push Button

Software

  • RSLogix 500

Components to Resolve

  • Which inputs and output the system will utilize?
  • What logic do we need to write in order to achieve the system operation described below?

System Operation

  1. The Motor is tied to the three phases of the Motor Contactor.
  2. When the Motor Contactor is energized, the motor is started.
  3. When the Motor Contactor is de-energized, the motor is stopped.
  4. The operator is able to push the start or the stop push buttons.
Take Hint #1.
Take Hint #2
Concept Review
Community Forum

Still have questions? Check out the

View this exercise's thread in the SolisPLC Forum
Show Answer
Hide Answer

We've selected the 1763-L16BWA MicroLogix 1100 PLC as our control system.

Step 1 - Review the datasheet and figure out how to connect the system.

By searching Google for the "MicroLogix 1100 1763-L16BWA datasheet", we find the following manual: MicroLogix 1100 Installation Instructions

On page 17, we find the following wiring diagram for the PLC. Note: Make sure to refer to the "1763-L16BWA" diagram.

MicroLogix 1100 1763-L16BWA Wiring Diagram
MicroLogix 1100 1763-L16BWA Wiring Diagram

We can conclude that we need to wire the two buttons ("Start" and "Stop") to the Input 0 (I/0)and Input 1 (I/1) of the PLC.

We can also conclude that we need to wire the motor contactor onto the Output 1 (O/0) of the PLC.

Note:

  • We'll need to supply the PLC with 110 VAC
  • We'll need to supply the "DC COM" with VDC- or VDC+ depending on the button polarity.
  • We'll need to supply the Output 1 with 24VDC+ and the coil with a GND to pull in the contactor once we energize the output.

Based on the above, the following drawing can be created.

MicroLogix 1100 1763-L16BWA Motor Starter Circuit Wiring Diagram
MicroLogix 1100 1763-L16BWA Motor Starter Circuit Wiring Diagram

Step 2 - Programming the PLC

We can go online with the PLC through an EtherNet or RS232 connection. We've created a complete tutorial on how to establish communication with a MicroLogix PLC, set the IP address and to go online. You may review the information here: Getting Started in RSLogix 500 & MicroLogix 1100 Programmable Logic Controller

Step 2.1 - Open RSLogix 500 and Create a New Program

New RSLogix 500 PLC Program - MicroLogix 1100 PLC
New RSLogix 500 PLC Program - MicroLogix 1100 PLC

Step 2.2 - Identify & Label all the I/O Points

"Start" Push Button on Input 0

"Start" Push Button on Input 0 of the PLC
"Start" Push Button on Input 0 of the PLC

"Stop" Push Button on Input 1

"Stop" Push Button on Input 1 of the PLC
"Stop" Push Button on Input 1 of the PLC

Motor Contactor on Output 0

Motor Contactor on Output 0 of the PLC

Step 2.3 - Build the Ladder Logic

Note: it is possible to solve this problem multiple ways. However, we recommend using the following structure that optimizes the use of the XIC and OTE instructions.

Note2: Since our "Stop" push button is Normally Closed, we use an XIC for the state of that signal. In many online examples, you'll see this instruction implemented as XIO. That's due to the fact that the button is Normally Open.

RSLogix 500 Motor Starter PLC Program

Step 2.3 - Download Logic to PLC & Go Online

We've outlined the steps on how to go online with a MicroLogix 1100 PLC in a separate tutorial. In this case, we're going to use the Emulate 500 software that can be downloaded and installed for free. We're written an extensive tutorial on how to download and install it: Download RSLogix 500, RSLogix 500 Emulate, and RSLinx for free

Once you've set the path, go online with the controller.

MicroLogix 1100 PLC Motor Starter Example
MicroLogix 1100 PLC Motor Starter Example

Step 2.4 - Test the Logic

We test our logic in the emulator by activating the appropriate inputs and watching the state of the output. In the real world, we could wire the buttons and use them to test the inputs and outputs.

Test 1 - Press the "Start" push button.

Expected Outcome - Motor Starter Energized.

Motor Starter Logic Test - "Start" Push Button Pressed
Motor Starter Logic Test - "Start" Push Button Pressed

Outcome - The Motor Starter is energized and the Motor is Running.

Test 2 - Release the "Start" push button.

Expected Outcome - Motor Starter Stays Energized.

Motor Starter Logic Test - "Start" Push Button Release
Motor Starter Logic Test - "Start" Push Button Released

Outcome - The Motor Starter stays energized and the Motor is Running.

Test 3 - Press the "Stop" push button.

Expected Outcome - Motor Starter is de-energized.

Motor Starter Logic Test - "Stop" Push Button Pressed
Motor Starter Logic Test - "Stop" Push Button Pressed

Outcome - The Motor Starter is de-energized and the Motor is Stopped.

Test 4 - Release the "Stop" push button.

Expected Outcome - Motor Starter stays de-energized.

Outcome - The Motor Starter stays de-energized and the Motor is Stopped.

Instructure:
Vladimir Romanov
Back to Challenges