CCW TUTORIAL
Micro800 in Connected Components Workbench: Your First Ladder Program (Video)
Rockwell Automation's own lesson on building and simulating a Micro800 project, with a written companion: every step of a first start/stop rung, on an all-free toolchain.
This CCW tutorial takes you through a first Micro800 ladder program on an entirely free toolchain: Connected Components Workbench (CCW) Standard Edition, which Rockwell offers as a free download, and its demo Micro800 Simulator. You will build a start/stop circuit with a seal-in, download it to the simulator and prove it works, with no PLC on the desk.
In this lesson by Rockwell Automation, the second of its four CCW basics videos, you see a project created with structured text, function block diagram and ladder, then tested in the Micro800 Simulator. Watch it once to see where things are in CCW. Then follow along, and check your work against the steps below.
What you need
- A Windows PC with CCW Standard Edition, downloaded from Rockwell's Product Compatibility and Download Center (PCDC). Rockwell lists the Standard Edition as free and says it includes a demo version of the Micro800 Simulator.
- About an hour.
- No hardware. The simulator stands in for a Micro820, Micro850 or Micro870.
This is the same toolchain our free Micro800 with CCW course uses from its first module, whose practice task is to install CCW, activate it and run a one-rung program in the simulator.
The program: a motor start/stop with a seal-in
The circuit is the first thing every PLC programmer learns, because it contains the idea behind almost everything else: a rung can hold itself on.
- START_PB is a normally open push button. Pressing it makes the input true.
- STOP_PB is a normally closed push button in the real world, which means the input is true while nobody is pressing it.
- MOTOR is the output that would drive a contactor.
The rung reads: MOTOR turns on if (START_PB is pressed or MOTOR is already on) and STOP_PB is not pressed. The "or MOTOR is already on" branch is the seal-in.
Step by step
1. Create the project. Start a new project and add a Micro800 controller from the catalogue. Pick the model you intend to simulate, since the simulator needs to match it.
2. Add a ladder program. Under the controller's Programs, add a new Ladder Diagram. CCW also offers function block diagram and structured text, which you will use later.
3. Declare the variables. Create three BOOL variables: START_PB, STOP_PB and MOTOR. In a real project these would map to physical I/O; in the simulator, simple variables you can change are enough for this exercise.
4. Draw the first branch. On rung 1, place a direct (normally open) contact for START_PB. Add a parallel branch beneath it with a direct contact for MOTOR.
5. Finish the rung. After the branch, place a contact for STOP_PB in series, then a direct coil for MOTOR at the right. Because the real stop button is normally closed, a direct contact on STOP_PB passes power while nobody presses it. If you prefer to treat STOP_PB as a simple "pressed" signal instead, use a reverse (normally closed) contact. Either works, as long as you know which one you chose and why.
6. Build. Build the project and fix anything the error list reports. Typical first-time errors are an undeclared variable or a coil that is not at the end of the rung.
7. Download and run. Connect to the Micro800 Simulator, download the program and put the simulated controller in run mode. The lesson above shows this part in Rockwell's own screens.
8. Test it. Use the variable monitor to set START_PB true, then false. MOTOR should come on and stay on. Now change STOP_PB so the rung breaks, and MOTOR should drop out. Watch the rung highlighting as you go: it shows power flow through each contact, which is the best way to see the scan in action.
Check your work
When it works, try the course's practice task: build the same start/stop in function block diagram and in structured text, the other two languages the video covers. In ST, the whole rung becomes one line of logic, and seeing that side by side with the ladder is what makes both languages click.
Common mistakes
- The motor will not stay on. The MOTOR contact must be in parallel with START_PB, not in series with it.
- STOP does nothing. Check which kind of contact you used for STOP_PB and what value the variable holds while nobody is "pressing" it.
- Two coils for MOTOR. If you write MOTOR in two rungs, the last one wins on every scan. Keep one coil per output.
Why this toolchain is worth your time
Everything in this lesson is free: CCW Standard and the demo Micro800 Simulator cost nothing. Rockwell also says CCW's ladder editing uses workflows similar to RSLogix 500 and Studio 5000 Logix Designer, so habits formed here carry into the larger Allen-Bradley software. The free Allen-Bradley courses cover RSLogix 500 and Studio 5000 too, for when you move beyond the Micro800.
Continue with the free course
The Micro800 with CCW course is free in full and runs from this first rung through latching, timers, counters, analog, user-defined function blocks, high-speed counters, motion and communications. Video lessons are by independent YouTube creators, including Rockwell Automation and Tim Wilborne, credited on the course page. EDWartens writes the notes, practice tasks and the final assessment: 15 questions, 60% to pass. After that, the Rockwell engineer path adds RSLogix 500 and Studio 5000.
The only paid item is an optional EDWartens Certificate of Completion after you pass. For this beginner course it costs from US$2.99, and checkout shows your price. Anyone can check it at edwartens.com/verification. It is not a Rockwell Automation certification, and it is not accredited.
Take the free course
Questions
Is Connected Components Workbench free?
The Standard Edition is. Rockwell lists it as a free download from its Product Compatibility and Download Center, and it includes a demo version of the Micro800 Simulator. The Developer Edition is a paid annual subscription.
Can I simulate a Micro800 without hardware?
Yes. CCW Standard includes a demo version of the Micro800 Simulator, which Rockwell describes as a basic environment for developing code without hardware. You download your program to it and run it like a real controller.
Which Micro800 controllers does CCW program?
Rockwell lists the Micro820, Micro850 and Micro870, along with PanelView 800 terminals and PowerFlex and Kinetix 5100 drives.
What languages does CCW support?
Ladder diagram, function block diagram and structured text. Rockwell's lesson in this post builds a project using all three and tests it in the Micro800 Simulator.
Why does my motor coil not stay on after I release START?
The seal-in branch is missing or wired to the wrong place. A contact of the MOTOR output must sit in parallel with the START contact, so the rung stays true once MOTOR is on.
Sources
- Rockwell Automation: Design and configuration software (CCW Standard and Developer editions)
- Rockwell Automation: CCW software tutorials
Written by the EDWartens engineering team for general education. Product names are trademarks of their owners; mentioning them does not imply endorsement. Prices and terms of other providers were checked on the date shown and can change.
