Code Review

Every change AI suggests goes through a review process. You're always in control of what gets applied to your code.

The Diff View

When AI generates or modifies code, the changes appear in a diff view that shows:

• Red lines - Code that will be removed
• Green lines - Code that will be added
• Gray lines - Unchanged context

FUNCTION_BLOCK FB_Motor
VAR_INPUT
    bStart : BOOL;
    bStop : BOOL;
+   bReset : BOOL;  // New input added by AI
END_VAR

VAR_OUTPUT
    bRunning : BOOL;
-   bError : BOOL;
+   bError : BOOL;
+   nErrorCode : INT;  // New output for error details
END_VAR

Review Workflow

Step 1: Review the Changes

Carefully examine each change:

• Does the code do what you asked?
• Are the variable names appropriate?
• Is the logic correct?
• Does it follow your coding standards?

Step 2: Make a Decision

You have three options for each change:

Step 3: Accept or Reject

• Click Accept to apply all changes
• Click Reject to discard all changes
• Use the edit feature to make modifications first

Editing Before Accepting

Sometimes AI gets it mostly right, but you want to make small adjustments:

1. Click Edit in the diff view
2. Make your modifications in the editor
3. Click Accept to apply your edited version

This is useful for:

• Fixing variable names
• Adjusting constants
• Adding comments
• Minor logic tweaks

Partial Acceptance

For larger changes, you may want to accept some parts and reject others:

1. Review the complete diff
2. Use the section controls to accept/reject individual hunks
3. Each hunk can be handled independently

Review Best Practices

Take Your Time

Don't rush through reviews. AI can generate plausible-looking code that has subtle bugs.

Check Logic Flow

Verify that:

• Conditions are correct (AND vs OR, > vs >=)
• Edge cases are handled
• State transitions make sense

Verify Data Types

Ensure:

• Variable types match their usage
• No implicit conversions that could cause issues
• Array bounds are appropriate

Look for Common Issues

Watch out for:

• Infinite loops
• Missing initialization
• Unhandled error conditions
• Off-by-one errors

History

PLC Studio AI keeps a history of all changes:

1. Go to History in the sidebar
2. See all accepted and rejected changes
3. Revert changes if needed

Keyboard Shortcuts

See the keyboard shortcuts reference for more.

Next Steps