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).