init

modbus.md

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+# Vevor D100 VFD - Modbus RTU Reverse Engineering Notes
+
+## Hardware
+
+* VFD: Vevor D100
+* Interface: RS485
+* Connection: USB-RS485 adapter
+* LinuxCNC version: 2.9.8
+
+## Communication Settings
+
+Configured on VFD:
+
+| Parameter     | Value      |
+| ------------- | ---------- |
+| Slave Address | 1          |
+| Baud Rate     | 9600       |
+| Data Bits     | 8          |
+| Parity        | None       |
+| Stop Bits     | 1          |
+| Protocol      | Modbus RTU |
+
+---
+
+# Addressing
+
+The VFD documentation uses hexadecimal Modbus addresses.
+
+Practical testing with `mbpoll` showed that mbpoll uses addresses shifted by +1 relative to the addresses shown in the manual.
+
+Formula:
+
+```text
+mbpoll_address = documented_hex_address + 1
+```
+
+Examples:
+
+| Documentation | Hex | mbpoll |
+| ------------- | --- | ------ |
+| 0200H         | 512 | 513    |
+| 0201H         | 513 | 514    |
+| 0210H         | 528 | 529    |
+| 0220H         | 544 | 545    |
+| 0221H         | 545 | 546    |
+| 0222H         | 546 | 547    |
+| 0223H         | 547 | 548    |
+
+---
+
+# Frequency Command
+
+Parameter:
+
+```text
+0201H = Given Frequency
+```
+
+mbpoll address:
+
+```text
+514
+```
+
+Manual example:
+
+```text
+01 06 02 01 0B B8
+```
+
+which means:
+
+```text
+3000 decimal = 300.0 Hz
+```
+
+---
+
+## F169
+
+Parameter:
+
+```text
+F169 = Given decimal point of communication frequency
+```
+
+Configured value:
+
+```text
+F169 = 0
+```
+
+Meaning:
+
+```text
+0201 = frequency * 10
+```
+
+Examples:
+
+| Frequency | Register Value |
+| --------- | -------------- |
+| 10.0 Hz   | 100            |
+| 25.0 Hz   | 250            |
+| 50.0 Hz   | 500            |
+| 100.0 Hz  | 1000           |
+| 300.0 Hz  | 3000           |
+
+---
+
+# Verified Read Registers
+
+## 0210H - Main Control Status
+
+mbpoll:
+
+```text
+529
+```
+
+Documentation:
+
+```text
+0210H
+Main control bit
+BIT0-BIT15 mapping parameter address 0000H-000FH
+```
+
+Verified values:
+
+### Stopped
+
+```text
+0210 = 0
+```
+
+Binary:
+
+```text
+0000 0000 0000 0000
+```
+
+### Running Forward
+
+```text
+0210 = 9
+```
+
+Binary:
+
+```text
+0000 0000 0000 1001
+```
+
+Meaning:
+
+```text
+BIT0 = Operation
+BIT3 = In operation
+```
+
+### Running Reverse
+
+```text
+0210 = 13
+```
+
+Binary:
+
+```text
+0000 0000 0000 1101
+```
+
+Meaning:
+
+```text
+BIT0 = Operation
+BIT2 = Reverse
+BIT3 = In operation
+```
+
+### Stopped After Reverse
+
+```text
+0210 = 4
+```
+
+Binary:
+
+```text
+0000 0000 0000 0100
+```
+
+Meaning:
+
+```text
+BIT2 = Reverse selected
+```
+
+---
+
+## 0220H Block
+
+mbpoll start address:
+
+```text
+545
+```
+
+Read command:
+
+```bash
+mbpoll -m rtu -a 1 -b 9600 -P none -t 4 -r 545 -c 4 /dev/ttyUSB0
+```
+
+Mapping:
+
+| Address | Function         |
+| ------- | ---------------- |
+| 0220H   | Output Frequency |
+| 0221H   | Set Frequency    |
+| 0222H   | Output Current   |
+| 0223H   | Output Speed     |
+
+mbpoll:
+
+| Address | Register         |
+| ------- | ---------------- |
+| 545     | Output Frequency |
+| 546     | Set Frequency    |
+| 547     | Output Current   |
+| 548     | Output Speed     |
+
+Verified example while running:
+
+| Register | Value |
+| -------- | ----- |
+| 545      | 1266  |
+| 546      | 1267  |
+| 547      | 214   |
+| 548      | 7602  |
+
+Interpreted as:
+
+| Parameter        | Value    |
+| ---------------- | -------- |
+| Output Frequency | 126.6 Hz |
+| Set Frequency    | 126.7 Hz |
+| Output Current   | 21.4 A   |
+| Output Speed     | 7602 RPM |
+
+---
+
+# 0200H Main Control Register
+
+Documentation:
+
+```text
+0200H Main control bit
+BIT0-BIT7 mapping parameter address 0048H-004FH
+```
+
+Bit mapping:
+
+| Coil | Name                   | Bit  | Decimal |
+| ---- | ---------------------- | ---- | ------- |
+| 0048 | Operation              | BIT0 | 1       |
+| 0049 | Forward                | BIT1 | 2       |
+| 004A | Reverse                | BIT2 | 4       |
+| 004B | Stop                   | BIT3 | 8       |
+| 004C | Forward/Reverse Switch | BIT4 | 16      |
+| 004D | JOG                    | BIT5 | 32      |
+| 004E | JOG Forward            | BIT6 | 64      |
+| 004F | JOG Reverse            | BIT7 | 128     |
+
+---
+
+# Verified Control Commands
+
+Control register:
+
+```text
+0200H
+```
+
+mbpoll address:
+
+```text
+513
+```
+
+---
+
+## Forward Run
+
+Command:
+
+```bash
+mbpoll -m rtu -a 1 -b 9600 -P none -t 4 -r 513 /dev/ttyUSB0 2
+```
+
+Writes:
+
+```text
+0200 = 2
+```
+
+Result:
+
+```text
+Forward Run
+```
+
+---
+
+## Reverse Run
+
+Command:
+
+```bash
+mbpoll -m rtu -a 1 -b 9600 -P none -t 4 -r 513 /dev/ttyUSB0 4
+```
+
+Writes:
+
+```text
+0200 = 4
+```
+
+Result:
+
+```text
+Reverse Run
+```
+
+---
+
+## Stop
+
+Command:
+
+```bash
+mbpoll -m rtu -a 1 -b 9600 -P none -t 4 -r 513 /dev/ttyUSB0 8
+```
+
+Writes:
+
+```text
+0200 = 8
+```
+
+Result:
+
+```text
+Stop
+```
+
+---
+
+## Toggle Direction
+
+Command:
+
+```bash
+mbpoll -m rtu -a 1 -b 9600 -P none -t 4 -r 513 /dev/ttyUSB0 16
+```
+
+Writes:
+
+```text
+0200 = 16
+```
+
+Result:
+
+```text
+Toggle Direction
+```
+
+Important:
+
+The toggle works only on a rising edge.
+
+To trigger it again:
+
+```text
+0200 = 0
+0200 = 16
+```
+
+must be sent.
+
+---
+
+# LinuxCNC Relevant Registers
+
+## Write
+
+| Function        | Documented | mbpoll |
+| --------------- | ---------- | ------ |
+| Main Control    | 0200H      | 513    |
+| Given Frequency | 0201H      | 514    |
+
+## Read
+
+| Function         | Documented | mbpoll |
+| ---------------- | ---------- | ------ |
+| Status           | 0210H      | 529    |
+| Output Frequency | 0220H      | 545    |
+| Set Frequency    | 0221H      | 546    |
+| Output Current   | 0222H      | 547    |
+| Output Speed     | 0223H      | 548    |
+
+---
+
+# RapidChange ATC Notes
+
+Useful registers for future ATC implementation:
+
+## Current
+
+```text
+0222H
+```
+
+Can potentially be used to detect:
+
+```text
+tool tightening
+tool loosening
+stall condition
+```
+
+based on current increase.
+
+## Status
+
+```text
+0210H
+```
+
+Can be used instead of fixed delays.
+
+Example:
+
+Wait until:
+
+```text
+BIT3 = 0
+```
+
+before moving after spindle stop.
+
+This is more reliable than:
+
+```text
+G4 P2
+```
+
+fixed delay logic.
+
+---
+
+# Known Issues
+
+RS485 communication becomes less reliable when spindle is running.
+
+Observed:
+
+```text
+Timeouts
+CRC errors
+Dropped frames
+```
+
+Likely causes:
+
+* EMI from spindle motor cables
+* insufficient cable separation
+* missing shield grounding
+* missing termination resistor
+
+Communication is stable when spindle is stopped.