Nidec Unidrive M700/M701/M702 frequency converter

Basic compliance and document positioning

Manufacturer and Qualification

Producer: Nidec Control Techniques Limited (UK)

Compliance System: ISO 14001, RoHS, REACH, WEEE, Conflict Mineral Management

Authoritative certifications: CE, UL/cUL, RCM, EAC, the original English version is the legal original document

Product positioning

Series: Unidrive M700/M701/M702 Universal High Performance AC Inverter

Drive objects: asynchronous induction motor, permanent magnet synchronous motor, linear motor

Core differences:

M700: Ethernet+Single Channel STO

M701: RS485 (Modbus RTU)+Single Channel STO

M702: Ethernet+Dual Channel STO

Safety regulations (mandatory requirement)

Core safety function: Safe Torque Off (STO)

Level: SIL 3, Cat 4, PL e, compliant with EN 61800-5-2, EN ISO 13849-1

Function: Cut off the motor torque output and achieve category 0 stop

Channel: M700/M701 single channel; M702 dual channel

Response time: Typical 8ms, maximum 20ms

Electrical safety

After power failure, wait for * * ≥ 10 minutes * * to release the capacitor charge

The control circuit is based on insulation, and external SELV equipment must be isolated

Grounding: 3 types of independent grounding, single ended grounding of shielding layer

Mechanical safety

Except for STO, all functions cannot be used for personal safety protection

Prohibited installation in hazardous environments, maintenance requires permission control

Core specifications of the product

operation mode

Open loop vector/V/F

RFC-A (Asynchronous Flux Control, with/without sensors)

RFC-S (Synchronous Flux Control, with/without sensors)

Regen (regenerative rectification mode)

Key rated parameters

|Project | Key Values|

|Voltage level | 200V, 400V, 575V, 690V|

|Switching frequency | 2~16kHz (automatic frequency reduction for safety)|

|Current rating | Dual rating for heavy/light load|

|Thermal protection | I2t low-speed thermal protection (15%/50% base speed switching)|

|Feedback support | AB, UVW, SinCos, EnDat, Hiperface, SSI, BiSS, Resolver|

|Expansion | Up to 3 optional modules, supporting bus I/O、 Encoder|

Installation and wiring

Mechanical Installation

Module installation sequence: Slot 3 → 2 → 1

Large modules can only be installed in slot 3

Keyboard supports hot swapping (in non keyboard mode)

RTC keyboard battery: CR2032, low battery prompt for replacement

Electrical installation

24V power supply: 19.2~28V, maximum 40~60W

Analog I/O: ± 10V/4~20mA, 12 bit resolution

Digital I/O: 24V logic, IEC 61131-2 Type 1

STO wiring: dual 24V, low state ≤ 5V to ensure safety

communication

M700/M702: Dual RJ45 Ethernet, supporting CAT5e

M701: Dual RJ45 RS485, Modbus RTU only

Operation and Menu System

human-machine interface

Keyboard: Two line LCD, directional keys+confirm+exit+start stop

Status display: Prohibit/Ready/Run/Trip

Quick access: Long press Enter to directly jump to parameters

Menu Architecture

Menu 0: Basic Common Parameters (Acceleration/Deceleration, Limiting, Reference Source)

Menu 1~21: Advanced features (speed, torque, I/O, PLC)

Menu 24+: Ethernet configuration (M700/M702)

Security Lock: Password Lock for Read and Write Permissions, Level 5 Access Control

key operation

Save parameter: Pr mm.000=1001

Restore default: 1233 (50Hz)/1244 (60Hz)

Change control mode: 1253/1254+reset

Motor debugging and operation

Quick Start Process

Input motor nameplate parameters (voltage, current, frequency, speed, number of poles)

Set maximum speed/frequency, acceleration/deceleration time

Configuration feedback (closed-loop)

Perform self-tuning

Enable STO and provide running instructions

Self tuning mode

Static setting: available with load, measure resistance/inductance

Rotation tuning: Recommended for no-load testing, measuring power factor/saturation characteristics

Setting code: 1=stationary, 2=rotating

Control method

Open loop: V/F, open-loop vector, low-frequency torque boost

RFC-A: Asynchronous closed-loop/sensorless, zero speed full torque

RFC-S: Permanent magnet motor closed-loop/sensorless, high-precision positioning

Advanced features

communication bus

Ethernet: Modbus TCP, EtherNet/IP, Profinet IO, RTMoE

RS485：Modbus RTU， Baud rate 300~115200

IP configuration: DHCP automatic/static, dual port switch

NV storage card

Function: Parameter backup, copying, program download

Operation: Save to files 1-3, load, compare, format

Onboard PLC

Standard: IEC 61131-3

Tool: Machine Control Studio

Function: Logic control, timer, counter scope

Diagnosis and fault handling

status indicator

Ready: Ready to run

Prohibit: STO not enabled/prohibited

Trip: Fault shutdown, displaying fault code

Typical faults

Overcurrent, Overvoltage, Overload, Overheating

Communication loss, abnormal feedback, I/O failure

Motor thermal insulation and brake resistor overheating

troubleshooting tool

Fault History Record

Real time monitoring: current, torque, speed, bus voltage

Non default parameter filtering, target parameter filtering

Certification and Application Licensing

STO certification

T Ü V certification, applicable to the highest level of mechanical safety

Elevator certification: Complies with EN 81-20 and can be used for elevator drive

UL Certification

File number: FSPC.E171230

Applicable: industrial drive, fan, water pump, material conveying

Key questions and answers

Question 1: What are the core hardware and functional differences among M700/M701/M702?

Answer: The core differences among the three are concentrated in communication interfaces and secure channels:

M700: Ethernet communication+single channel STO, supporting EtherNet/IP, Profinet, etc

M701: RS485 (Modbus RTU)+single channel STO, used for upgrading and replacing traditional serial ports

M702: Ethernet communication+dual channel STO, meeting the highest level of safety circuit requirements

The control algorithms, motor compatibility, and parameter structure of the three are completely consistent.

Question 2: What are the usage restrictions and correct wiring principles for the STO safety torque shutdown function?

answer:

Usage restrictions: Only used for cutting off torque, not isolating high voltage; Maintenance must be powered off and locked; No personal safety protection is allowed for any function other than STO.

Wiring principle:

M702 must use dual channel independent wiring to avoid single point failure failure

Low level must be * * ≤ 5V, ≤ 0.5mA * * to meet SIL3/PL e

Dedicated grounding, shielded cable, separated from power line by ≥ 100mm

The maximum response time is 20ms and cannot be used for real-time safety control other than emergency stop

Question 3: What are the minimum necessary parameters and steps for a frequency converter to start quickly and run stably?

answer:

Required parameters (5)

Pr 00.044 motor rated voltage

Pr 00.046 motor rated current

Pr 00.047 motor rated frequency

Pr 00.045 motor rated speed

Pr 00.002 maximum speed/frequency limit

The simplest steps

Correctly complete the power and STO wiring

Write the above 5 parameters

Perform rotation self-tuning (Pr 00.040=2)

Set acceleration and deceleration time (Pr 00.003/004)

Save parameter (1001) and reset

Enable STO → give running instructions