Modbus spindle control using the Sunfar E500 and PLCM-B1-G2 expansion board
You will need a frequency converter (hereinafter referred to as the FC) with support for Modbus RTU control, such as Sunfar E500, to control the spindle via Modbus via the PLCM-B1-G2 expansion board.
Modbus spindle control setting procedure:
- Set FC to the control mode using the Modbus RTU protocol (RS-485) and remember the COM port settings in FC (count of bits per second, data bits, parity and stop bits).
Example for Sunfar E500.
| Function code | Value | Description |
|---|---|---|
| F0.00 | 2 | Frequency reference source - external data transfer |
| F0.02 | 0002 | Trigger channel selection - serial data port |
| F4.00 | 0114 | Data transfer settings - speed selection: 9600 bps, parity check, Modbus data transfer protocol |
2. Connect FC to the PLCM-B1-G2 expansion board via RS-485 interface.
3. Purchase the "MODBUS protocol support" option or activate a trial period for this option in the menu "Configuration" → "License Manager" → "Common".
4. Enable and configure Modbus in the menu "Configuration" → "Modbus Setup".
Create new Modbus-master. Number of COM port is PLCM. The rest of the settings should be exactly the same as in the FC (in the screenshot, an example of a standard configuration of the COM port of Sunfar E500).
You need to add registers to control the FC and read statuses from FC. For example you need to configure registers named SpindleMode, SpindleRPM and SpindleStatus.
We recommend using exactly these names, since in the future, registers will be accessed from background operations by their names.
5. Create new background operation (macro) through the macro manager.
The main task of the background macro is to monitor the current state and spindle speed and send the values to the frequency converter via Modbus.
An example of background operation modbus_spindle.bm for ModBus spindle control posted in attachment. This file must be added to background operations list.
6. Enable the background operation. Make sure that the operation has started and is working properly. This will be indicated by the green indicator to the right of the operation name.
The spindle should now turn on and off if everything is configured correctly. The spindle speed accordingly must also change at the FC when it changing in PUMOTIX.