To download to an AC500-eco: build the project, choose Online > Login and confirm the download when asked, then start the CPU with Online > Run. On V2 eco CPUs also choose Online > Create boot project, otherwise the program is lost after power off. V3 CPUs create the boot application at download by default.
- Build first: never download a project with errors or unchecked warnings
- Login compares PC and PLC: it offers online change when only logic changed
- On V2 eco CPUs, Create boot project is a separate step and must not be forgotten
- Power-cycle test: the CPU must come back in RUN with your program
The single most common commissioning surprise on AC500 V2 CPUs is a machine that works perfectly until the next morning, when power is switched on and the CPU is empty. The cause is a missing boot project, and this lab makes it a habit.
Step 1: Build and Fix Errors
- Choose Rebuild all for the application.
- Read the message window: errors stop the download, warnings should be understood.
- Double-click a message to jump to the line or rung.
| Typical message | Meaning | Fix |
|---|---|---|
| Identifier not defined | Variable name typed wrong or not declared | Correct the name or map/declare it |
| Type mismatch | BOOL used where INT expected or similar | Use the right variable or conversion |
| Variable written in several POUs (warning) | Double coil | Write the output in one place only |
| Configuration differs from device | Hardware tree does not match CPU | Fix CPU type, firmware or modules |
Step 2: Log In and Download
- Choose Online > Login.
- Automation Builder compares the project with the one in the CPU. If they differ it asks whether to download: choose Yes.
- Watch the progress bar. When finished the editor is online and the CPU is in STOP.
- Choose Online > Run. The RUN LED lights.
| Option | When it is offered | What happens | Use it when |
|---|---|---|---|
| Full download | Hardware or many changes | CPU stops, whole program replaced, data reinitialised | First download, configuration changes |
| Online change | Only logic changed | Changed code loaded while running, data kept | Small logic fixes on a running machine (with care) |
| Login without change | Projects identical | Monitoring only | Fault finding |
Step 3: Create the Boot Project
The download goes into the CPU's working memory. On AC500 V2 CPUs (including PM564-ETH) it must also be written to flash as a boot project, which is loaded at power up.
- While logged in, choose Online > Create boot project.
- Wait for the confirmation; do not switch off during this step.
- Optional: also use Online > Sourcecode download so the project source is stored in the CPU for upload in Lab 9.
| CPU generation | Boot project behaviour |
|---|---|
| AC500-eco V2 (PM55x/PM56x) | Manual: Online > Create boot project after every download you want to keep |
| AC500-eco V3 (PM50xx) | Boot application normally created automatically at download (setting in the project) |
Step 4: Power Cycle Test
| ID | Check | How to check | Pass criterion | Result |
|---|---|---|---|---|
| Download proof | ||||
| D-01 | RUN after download | Online > Run | RUN LED on, start/stop logic works | |
| D-02 | Boot project | Create boot project | Confirmation shown, no error | |
| D-03 | Power cycle | Switch CPU supply off for 10 s, then on | CPU returns to RUN with logic working | |
| D-04 | Project match | Log in again | No download prompt: PC and PLC identical | |
Practice Exercise
Change the Start lamp to flash while the motor runs (use a BLINK or timer pair). Try it once as an online change and once as a full download, and note which one keeps the motor running.
Troubleshooting
| Symptom | Likely cause | Fix |
|---|---|---|
| Program gone after power off | No boot project (V2) | Online > Create boot project after download |
| Download refused: configuration differs | CPU type or firmware mismatch | Match the device tree to the real CPU |
| CPU stays in STOP after power up | CPU parameter for start mode, or error | Check the start-up parameter and the error LED/log |
| Login keeps asking to download | Project changed after last download | Download again, or check you opened the right project version |
Frequently asked questions
How do I download a program to an ABB AC500 PLC?
Build the project, select Online > Login, confirm the download prompt, then start the CPU with Online > Run. On V2 CPUs also create a boot project.
Why is my AC500 program lost after power off?
On AC500 V2 CPUs the program must be stored with Online > Create boot project. Without it, the CPU loads nothing at power up.
What is online change in Automation Builder?
A way to load changed logic while the CPU keeps running and keeps its data. It is offered when only code changed; hardware changes need a full download.
Can I download without stopping the machine?
Only with an online change, and only after checking the change is safe for the running process.