INVT Goodrive35 Series User Manual

Goodrive35 Series Closed-loop Vector Control VFD Communication protocol
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10.3.2 RTU mode
10.3.2.1 RTU communication frame format
If the controller is set to communicate by RTU mode in Modbus network every 8bit byte in the
message includes two 4Bit hex characters. Compared with ACSII mode, this mode can send more
data at the same baud rate.
Code system
1 start bit
7 or 8 digital bit, the minimum valid bit can be sent firstly. Every 8 bit frame includes two hex
characters (0...9, A...F)
1 even/odd check bit. If there is no checkout, the even/odd check bit is inexistent.
1 end bit (with checkout), 2 bit (no checkout)
Error detection field
CRC
The data format is illustrated as below:
11-bit character frame (BIT1–BIT8 are the data bits)
Start bit
BIT1
BIT2
BIT3
BIT4
BIT5
BIT6
BIT7
BIT8
Check bit
End bit
10-bit character frame (BIT1–BIT7 are the data bits)
Start bit
BIT1
BIT2
BIT3
BIT4
BIT5
BIT6
BIT7
Check bit
End bit
In a character frame, only the data bits carry information. The start bit, check bit, and end bit are used
to facilitate the transmission of the data bits to the destination device. In practical applications, you
must set the data bits, parity check bits, and end bits consistently.
In RTU mode, the transmission of a new frame always starts from an idle time (the transmission time
of 3.5 bytes). On a network where the transmission rate is calculated based on the baud rate, the
transmission time of 3.5 bytes can be easily obtained. After the idle time ends, the data domains are
transmitted in the following sequence: slave address, operation command code, data, and CRC
check character. Each byte transmitted in each domain includes 2 hexadecimal characters (0–9, A–F).
The network devices always monitor the communication bus. After receiving the first domain (address
information), each network device identifies the byte. After the last byte is transmitted, a similar
transmission interval (the transmission time of 3.5 bytes) is used to indicate that the transmission of
the frame ends. Then, the transmission of a new frame starts.
RTU data frame format
Modbus packet
Start with an idle time (at
least the transmission
time of 3.5 bytes)
Slave
address
Function
code
Data Check
End with an idle time (at
least the transmission
time of 3.5 bytes)

INVT Goodrive35 Series Specifications

General

Protection Level	IP20
Power Range	0.75kW ~ 630kW
Control Mode	SVC
Overload Capacity	150% for 60 seconds, 180% for 10 seconds
Braking Unit	Built-in or external optional braking unit
Communication Protocol	Modbus
Protection Features	Overvoltage, Undervoltage, Overcurrent, Overload, Overtemperature, Short Circuit, Phase Loss
Ambient Temperature	-10°C to +50°C
Humidity	Less than 95% RH (non-condensing)
Altitude	Below 1000m (derating above 1000m)
Cooling Method	Forced air cooling

Summary

Chapter 1 Safety precautions

1.4 Safety guidelines

General rules and precautions for operating the VFD safely.

Chapter 2 Quick start-up

2.4 Environment

2.5 Installation confirmation

Checks to perform after the VFD has been physically installed.

2.6 Basic commission

Essential commissioning steps to perform before the VFD is put into actual operation.

Chapter 3 Product overview

3.3 Product specification

Details the technical specifications of the VFD across various functions.

3.6 Rated values

Lists electrical and performance ratings for different VFD models.

Chapter 4 Installation guide

4.2 Mechanical installation

Covers environmental requirements and installation methods for the VFD.

4.3 Standard wiring

Details the wiring diagrams for the main and control circuits of the VFD.

4.4 Standard wiring (control circuit)

Explains the wiring for various control circuit terminals and interfaces.

4.5 Wiring protection

Guidance on protecting the VFD and cables from electrical issues.

Chapter 5 Keypad operation procedures

5.2 Keypad

Details the VFD's keypad for control, data reading, and parameter modification.

5.3 Keypad displaying

5.4 Keypad operation

Instructions on how to navigate menus and modify VFD function codes.

Chapter 6 Function parameters

6.2 Goodrive35 general series function parameters

Detailed explanation of the VFD's function parameter groups and codes.

Chapter 7 Basic operation instruction

7.2 First powering on

Steps for initial power-up, checks, and VFD initialization.

7.3 Vector control

Explains the principles and application of vector control for asynchronous motors.

7.4 SVPWM control

7.5 Torque control

Covers the two control modes, torque and rotation speed control, and their implementation.

7.6 Parameters of the motor

Crucial motor parameters that need to be set for VFD operation and autotuning.

7.7 Start-up and stop control

Explains the different modes for starting and stopping the VFD.

7.8 Frequency setting

Describes various methods for setting the VFD's operating frequency.

Chapter 8 Fault tracking

8.3 How to reset

Methods for resetting VFD faults via keypad, digital input, or power cycling.

8.5 Fault instruction and solution

Steps to diagnose and resolve VFD faults, including tables of common faults.

8.6 Common fault analysis

Troubleshooting guides for common VFD issues like motor not working or vibration.

Chapter 9 Routine maintenance

9.2 Maintenance intervals

Lists recommended routine maintenance checks and their criteria.

Chapter 10 Communication protocol

10.2 Brief instruction to Modbus protocol

10.3 Application of the VFD

10.4 RTU command code and communication data illustration

Explains RTU frame formats, command codes, and data structure for communication.

10.5 Common communication fault