3.3 Test RS485 Output

Advanced Tests · Optional · Use a USB-to-RS485 adapter and VFD simulator to verify RS485 commands

ℹ️

Objective: This section verifies that the controller can send RS485 VFD commands correctly. A USB-to-RS485 adapter and a computer are required for this test.

⚠️

NOTE: Only the A and B wires are required for this test. If communication does not work, swap A and B, then try again.

Connect USB-to-RS485 Adapter

Connect the USB-to-RS485 adapter to your computer.
Connect the adapter A and B wires to the RS485 terminal on the controller board.
Use only two wires: A and B.
If the simulator shows no response later, swap A and B.

Open the VFD Simulator

Open the simulator website on your computer:
https://wiki.pibot.com/485-vfd-sim/
Use the default serial settings: 9600 8 N 1
Select the COM port of your USB-to-RS485 adapter and connect.

Reference image: RS485 VFD simulator page. Keep the default setting at 9600 8N1.

Send Test Commands from WebUI

Open the controller WebUI command line.
Send the following commands one by one.
After each spindle command, check whether the simulator display changes.

M6 T3 M3 S12000 M4 S24000

M6 T3 selects the RS485 / VFD test tool.
M3 S12000 starts spindle forward at 12000 RPM. The simulator should show a value change.
M4 S24000 starts spindle reverse at 24000 RPM. The simulator should show another value change.

✓

Expected Results

The USB-to-RS485 adapter connects to the simulator with default 9600 8N1 settings.
After M3 S12000, the simulator display changes.
After M4 S24000, the simulator display changes again.
If there is no response, swap the A and B wires and test again.

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