Huichuan H3U series PLC high-performance motion control selection and troubleshooting guide

Huichuan H3U series PLC high-performance motion control selection and troubleshooting guide

Against the backdrop of the rapid rise of domestic PLCs, Inovance's H3U series has become a popular choice for small and medium-sized automation equipment such as packaging machines, CNC machine tools, and electronic assembly lines, thanks to its high-performance motion control and rich communication interfaces. The H3U series has increased the basic instruction processing speed to 100 ns, with a program capacity of 64K steps, and supports two axis arc interpolation, three-axis point-to-point interpolation, and even electronic cam (only for high-end sports models). However, on-site engineers often encounter issues such as model differentiation, communication failures, and high-speed I/O configuration during selection, installation, debugging, and maintenance. This article is based on the official technical information of the H3U series, combined with practical application experience, to systematically sort out its characteristics, selection points, troubleshooting methods, and precautions for upgrading and replacing old PLCs.

Overview and Selection of H3U Series Products

1.1 Main models and positioning

The H3U series currently includes multiple sub models, with the core difference being its motion control capability and I/O points:

Model Basic Command Speed High speed Input High speed Output Motion Function Typical Applications

H3U-0808PRTA 100 ns 8 × 200 kHz 8 × 500 kHz three-axis electronic cam, spiral interpolation complex cam, flying shear, chasing shear

H3U-1616MT (Standard) 100 ns 8 × 200 kHz 4 × 200 kHz Two axis Arc Interpolation, Linear Interpolation Universal Point Position Motion Control

H3U-3232MT (Large I/O Type) 100 ns 16 × 200 kHz 8 × 200 kHz Two axis Arc/Line Interpolation Multi axis Equipment, Packaging Machinery

Selection key:

Electronic cam (electronic gear, flying shear, rotary cutting) must be selected with H3U-0808PMCTA (high-performance sport type).

Only point-to-point positioning or simple arc interpolation is needed, and the standard model can meet the requirements.

If the local I/O point requirement is greater than 32 points, GL10 series remote I/O modules can be selected for expansion, supporting a maximum of 7936 digital remote I/O.

1.2 Power Supply and Power Consumption

The controller body integrates a power supply (24V DC input) and does not require a separate power module. But to expand the GL10 series I/O, it is necessary to configure the GL10-PS2 power module (220V AC input, 2A/24V DC output) to provide bus power and peripheral power for the I/O module.

Attention: When using remote I/O stations, each slave station needs to calculate power consumption separately, and the total current must not exceed the rated value of the CANopen power supply.

Deep analysis of motion control function

2.1 High speed input/output configuration

H3U provides high-speed inputs up to 200 kHz (for encoder feedback, photoelectric switches, proximity switches) and high-speed pulse outputs up to 500 kHz (PMRTA type only). High speed output can be used to control stepper motors or servo drives.

Common faults: No pulse or incorrect number of pulses in high-speed output.

Troubleshooting steps:

Confirm the common termination method (source/drain) of the output point. H3U transistor output is source type (PNP). If the driver requires NPN signal, an intermediate relay or level converter needs to be installed.

Correctly configure the pulse frequency and number of high-speed output commands (such as PLSY, PLSR, DDRVA, DDRVI) in AutoShop software.

Check if the LED at the output point is flashing. If the LED is normal but the motor is not running, measure the voltage between the output terminal and the common terminal (24V should be present).

For 500 kHz high-speed output, shielded twisted pair cables must be used, and high-speed optocouplers should be connected to the driver side, otherwise signal distortion will cause step loss.

2.2 Electronic cam (high-end sports type)

H3U-0808PRTA supports electronic cam function, which can achieve nonlinear synchronization between the spindle (virtual shaft or actual encoder) and the slave shaft. Import cam table (256 points) through AutoShop software and perform real-time interpolation during runtime. Typical applications include: rotary cutting machines, flying cutters, and printing color matching.

Common problem: Excessive cam tracking error.

Solution:

Check if the spindle encoder signal is stable (it is recommended to use a differential encoder in high noise environments).

Improve the position loop gain of the servo drive.

Appropriately increase the number of interpolation points on the cam table.

Replace the cam with an electronic gear (if non-linear relationships are not required).

2.3 Interpolation Motion

Supports two axis arc interpolation and three-axis point-to-point interpolation (PMRTA can also achieve spiral curves). Programming instructions include LIN (Linear Interpolation), CIR (Circular Interpolation), MOVLINK, etc. It should be noted that interpolation motion requires two or more high-speed output channels, and the slave servo must support position mode (pt or pp).

Communication interface and network configuration

3.1 Integrated Communication Port

Purpose of Interface Protocol

Ethernet MODBUS TCP (server/client) connection for HMI, SCADA, PC programming

RS485 × 2 MODBUS RTU (master/slave) connection to frequency converter, instrument, touch screen

CAN CANopen (main station), CANlink (Huichuan proprietary) remote I/O, servo drive, sensor

USB programming port (mini USB) for downloading programs and online monitoring

CANlink is a proprietary protocol of Huichuan, used to connect Huichuan servo (IS620 series) and frequency converter (MD500 series), supporting position synchronization and parameter read-write. Unlike CANopen, CANlink does not require configuring an object dictionary and is suitable for fast networking.

3.2 Remote I/O Expansion

Through the CANopen protocol, H3U can serve as the main station to connect GL10 series remote I/O modules, including:

Digital input (16/32 points, optional PNP/NPN)

Digital output (relay or transistor)

Analog input/output (4-channel)

Temperature detection (PT100, thermocouple)

Pulse output positioning module (4-channel 200 kHz)

The maximum expandable capacity is 7936 digital I/O and 1488 analog I/O, meeting the requirements of large equipment.

Common communication failure: CANopen network cannot recognize the slave station.

troubleshoot

Check the terminal resistance (120 Ω parallel connection at both ends).

Confirm that the slave node ID and baud rate (default 125 kbps, 250 kbps, or 500 kbps) are consistent with the master station settings.

Measure the differential voltage between CAN-H and CAN-L using an oscilloscope (implicit 2.5V, explicit approximately 1.5V/3.5V).

Check if the power supply of the slave station is normal (GL10 module requires external 24V).

3.3 Ethernet Communication Settings

H3U's Ethernet port supports MODBUS TCP (client and server) and can be used to exchange data with configuration software, smart meters, or other PLCs.

Configuration steps (AutoShop):

Open "Ethernet Configuration" in the engineering tree and set the IP address (such as 192.168.1.100) and subnet mask.

If used as a MODBUS TCP server, select "Enable MODBUS TCP Server" and the default port is 502.

If used as a client, use the MB_TCP_SSG instruction to read and write to remote devices.

Fault case: HMI cannot read H3U data.

Reason: IP address conflict or firewall blocking port 502. Check network settings and try ping command.

I/O configuration and wiring

4.1 Local I/O

The number of I/O points on the H3U body varies depending on the model (e.g. 0808:8 in and 8 out; 1616:16 in and 16 out; 3232:32 in and 32 out). The input is compatible with drain/source type (common terminal can be connected to 0V or 24V), and the output is transistor source type (PNP, common terminal connected to 0V).

Connection Notes:

Input using 24V DC, it is recommended to use shielded wires to prevent false signals.

When driving the relay coil, a freewheeling diode (such as 1N4007) must be connected in parallel at both ends of the coil, otherwise the output point will be damaged.

4.2 Remote I/O Configuration

Connect GL10 series modules through CANopen bus. Each module occupies a node address and needs to be set using a dip switch. Device configuration must be performed in AutoShop (adding CANopen master and scanning slave).

Common error: Remote I/O input signal cannot be read.

Solution: Check the EMCY error message and confirm if the module is in the 'operation' state. If the module LED displays red, reconfigure the object dictionary or update the firmware.

Key points for using programming software AutoShop

5.1 Supported Languages

AutoShop complies with the IEC 61131-3 standard and supports:

LD (ladder diagram)

IL (Instruction List)

SFC (Sequential Function Diagram)

Motion control instructions (such as DDRVI, DDRVA, PLSR) are called in ladder diagram form.

5.2 Program Download and Online Modification

Download the program through a mini USB cable (H2U-USB-CAB) or Ethernet.

Fault: Unable to connect to PLC.

troubleshoot

Select the correct communication interface (USB or Ethernet) in AutoShop.

If using USB, it is necessary to install the Huichuan USB driver (included in the software installation package).

Attempt communication testing, if unsuccessful, check the PLC power supply and indicator lights (POWER on, RUN flashing or constantly on).

If the PLC is in STOP state, turn the mode switch to RUN.

5.3 Online monitoring and debugging

AutoShop provides online monitoring, breakpoint debugging, and waveform analysis (capturing high-speed output pulses). When debugging motion control, it is recommended to first test each axis direction with jogging, and then execute interpolation instructions.

Summary of common troubleshooting

Possible causes and solutions for the fault phenomenon

PLC has no response when powered on. The power supply voltage is low or the internal fuse is burnt out. Measure the 24V input and check if the internal battery H2U-BAT is short circuited

RUN LED not on, program error or mode switch in STOP. Turn the switch to RUN and check for program compilation errors

High speed output without pulse load short circuit, damaged output transistor, disconnected load, measured output voltage, replaced damaged point

CANopen slave offline terminal resistor not connected, address conflict, inconsistent baud rate. Add a 120 Ω resistor and rescan the node

Electronic cam asynchronous spindle encoder interference, insufficient use of shielded wires for cam gauge points, increased cam gauge density

AutoShop cannot download USB driver not installed, cable failure reinstalls driver, switch to H2U-232-CAB serial port cable

Remote analog module reading abnormal range configuration error, module not calibrated check GL10-4AD/4DA input range setting, perform calibration

Replacement and Upgrade Guide

7.1 Upgrading from H1U/H2U to H3U

The Huichuan H1U/H2U series were early products that were gradually discontinued. When upgrading to H3U, please note:

Hardware replacement: H3U installation size is compatible with H2U, but there is a slight change in the definition of I/O wiring terminals, and the position of the common terminal needs to be checked.

Program porting: The H1U/H2U instruction set is mostly compatible with H3U, but certain special features (such as the high-speed counting instruction HSC) need to be modified. AutoShop provides a conversion wizard that automatically checks for incompatible commands.

Communication protocol: H2U's CANlink protocol is fully compatible with H3U, and remote I/O modules can continue to be used.

Program capacity: H1U has a maximum of 8K steps, H3U has 64K steps, but the original program may need to optimize the scanning cycle (because H3U is faster and timing sensitive programs need to adjust the timer).

7.2 Replacement of third-party PLC (such as Mitsubishi FX3U)

H3U is highly similar in command to Mitsubishi FX3U, but not 100% compatible. Attention should be paid during transplantation:

Software component range: Mitsubishi's M8000 and other special relays may correspond to different addresses in H3U, please refer to the mapping table in the Huichuan manual.

Positioning instruction: DDRVA and DDRVI parameters have the same order, but there may be differences in acceleration and deceleration time units.

MODBUS command: Mitsubishi uses RS command, H3U uses MODBUS function block.

Recommended practice: completely rewrite the program and utilize AutoShop's ladder diagram editing function instead of directly converting.

Maintenance and spare parts recommendation

8.1 Battery replacement

H3U uses CR2032 lithium batteries (with leads, model H2U-BAT) to maintain real-time clock and power-off data. When the battery voltage is low, the PLC will sound an alarm (special relay position). When replacing, it must be done while the PLC is powered on (hot plugging), otherwise the data will be lost. It is recommended to replace it every 3-5 years.

8.2 Regular Inspection

Clean the heat dissipation holes to prevent dust accumulation from causing overheating.

Check if the terminal screws are loose (recommended once a year).

For output points with frequent movements, regularly monitor the contact resistance.

8.3 Spare Parts List

Spare parts model and purpose

Battery H2U-BAT clock and data backup maintenance

Programming cable (USB) H2U-USB-CAB program download

Programming cable (RS232) H2U-232-CAB compatible with old PCs

Ethernet cable (3m) S6-L-T04-3.0 network communication

CANopen terminal resistor 120 Ω plug bus matching