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

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