+++
title = "Modbus - Errors"
weight = 6
categories = "Modbus"
+++

## Error Codes

The system exposes the current error code as a Modbus register at address `0x00` (FunctionCode:0x3) :

- `E_VFD_TIMEOUT` = 1002
- `E_PID_TIMEOUT` = 2002
- `E_FEED_OVERLOAD` = 4001
- `E_VFD_OVERLOAD` = 1001

## System Debug Commands

| Name | Component ID  | Address | RW |  Function Code | Value |Register Description|
|------|----------|----|----|----|----|-------|
| System | 1 | 9 | -W | 0x6 | 1 | Print Modbus Queue  |
| System | 1 | 9 | -W | 0x6 | 2 | Print Component Modbus Registers  |
| System | 1 | 100 | -W | 0x6 | 1 | Reset Controller  |
| System | 1 | 19 | -W | 0x6 | 1 | Print PID controller states  |

See more details in the [PHApp::onError Implementation](../firmware/firmware_v2_cm/PHApp.cpp)