Application Case: Micro Diaphragm Pump Integrated Control System Based On Modbus Bus

Application Case: Micro Diaphragm Pump Integrated Control System Based on Modbus Bus

I. Abstract

In the modern industrial automation field, efficiently and reliably integrating and controlling decentralized actuators (such as pumps and valves) and sensors is a key challenge in enhancing overall equipment performance and intelligence levels. Traditional discrete control methods have inherent pain points, including complex wiring, numerous protocols, and difficult maintenance.

This case presents and validates an integrated solution based on the Modbus industrial bus. The core of this solution lies in adopting our company’s TS-CC intelligent speed controller, specifically designed for micro diaphragm pumps. The TS-CC speed controller acts as an “intelligent gateway” for micro diaphragm pumps to access the industrial bus network, enabling all compatible micro diaphragm pumps to be easily converted into standard Modbus slave devices. Through a single master controller (such as a PLC or industrial PC), centralized start/stop, precise speed regulation, status monitoring, and coordinated linkage with other Modbus devices (solenoid valves, sensors) can be achieved for multiple diaphragm pumps.

This solution significantly simplifies the system architecture, reduces wiring costs and debugging difficulty, improves control precision and system maintainability, making it an ideal choice for flexible production units geared towards Industry 4.0.

II. Project Background and Industry Requirements

In numerous industries such as fine chemicals, environmental water treatment, food and beverage, biopharmaceuticals, and laboratory automation, micro diaphragm pumps are widely used for fluid transfer, metering, and dispensing due to their compact structure, pollution-free operation, and ease of metering. Typical application systems often include multiple diaphragm pumps, multiple solenoid valves, and various sensors like liquid level, flow, and pressure sensors.

Main Challenges Faced by Traditional Control Modes:

Complex Wiring: Each pump and valve typically requires independent power lines and control signal lines (such as PWM or 0-10V), leading to cumbersome control cabinet wiring, dense on-site cabling, and difficult fault troubleshooting.
Non-Uniform Protocols: Devices from different manufacturers may support different communication or control protocols, requiring additional protocol conversion modules for integration, increasing system complexity and cost.
Poor Scalability: Adding or adjusting equipment requires rewiring and modifying the controller program, resulting in long modification cycles and affecting production flexibility.
Lack of Status Monitoring: Traditional simple speed regulation methods struggle to obtain real-time operational status of the pump (such as faults, overload), hindering predictive maintenance.

As a mature, open, and widely adopted industrial communication standard, the Modbus bus provides an excellent solution path for the above issues. Its master-slave architecture and ease of implementation make it the preferred network for achieving centralized control at the device level.

III. Technical Solution Design: Modbus Bus Integrated Control System

System Architecture

This solution adopts a standard Modbus RTU over RS-485 bus network (Modbus TCP/IP over Ethernet is also supported) to build a distributed control system with one master and multiple slaves.

[Master Controller (PLC/Industrial PC)]

Figure 1: System Topology Diagram

Control Logic

The master controller, acting as the Modbus master, periodically polls or communicates with each slave device based on event triggers.
Each TS-CC speed controller and the micro diaphragm pump it drives act as an independent slave node with a unique station address.
The master controller writes register values to the TS-CC speed controller at a specified station address to achieve start/stop control and speed setting (0-100%) for that pump.
Simultaneously, the master controller reads the registers of the TS-CC speed controller to obtain real-time information such as the pump’s actual speed, operating current, and fault status.
Based on feedback data from sensors (e.g., liquid level, flow), the master controller coordinately controls the actions of micro diaphragm pumps and solenoid valves via the bus, implementing complex process logic.

IV. Core Component Introduction: TS-CC Speed Controller

The TS-CC speed controller is the core intelligent interface unit of this integration solution, specifically designed to seamlessly upgrade our company’s micro diaphragm pumps into networked intelligent actuators.

Product Positioning: “Modbus Bus Intelligent Driver Card” for micro diaphragm pumps.

Key Features:

Full Protocol Compatibility: Natively supports Modbus RTU (RS-485) protocol for easy integration into existing industrial networks.
Precise Drive: Utilizes an efficient PWM drive circuit for stepless and smooth speed regulation of the micro diaphragm pump motor, offering high-speed control precision.
Comprehensive Feedback: Built-in current detection circuit allows real-time monitoring of pump operating current, featuring overcurrent protection, stall protection, and fault status reporting functions.
Industrial-Grade Design: Wide voltage input (5V/12/24VDC), features reverse polarity protection and overvoltage protection. Its compact housing facilitates easy installation and suits industrial field environments.
Plug-and-Play: Connects to specified model micro diaphragm pumps via a dedicated interface, eliminating complex wiring and debugging.
Dedicated PC Software: Convenient for debugging and configuration.

Technical Parameters Overview:

Communication Interface: RS-485 (Isolated)
Supported Protocol: Modbus RTU
Control Commands: Start/Stop, Speed Setting (0-100%)
Feedback Information: Actual Speed, Load Current, Fault Code
Power Input: 12/24 VDC

V. Micro Diaphragm Pump Product Series

Our company offers a full range of micro diaphragm pumps perfectly compatible with the TS-CC speed controller, meeting various flow, pressure, and media requirements.

Product Line Overview:

D Series Diaphragm Air Pumps: Used for transmitting gas or creating vacuum, typically suitable for gas transfer or gas sampling.
S Series Micro Diaphragm Liquid Pumps: Pump heads and diaphragms can be made of corrosion-resistant materials like PTFE for transferring various corrosive or neutral liquids.
DP-F Series: Food and pharmaceutical grade, meeting relevant hygiene standards, easy to clean and sterilize.

Core Advantages:

Seamless Compatibility: All models provide a standard interface for the TS-CC speed controller, ensuring connect-and-use capability.
High Performance: Long-life design, low power consumption, high reliability, and stable flow.
Easy Integration: Compact modular design facilitates embedding into equipment and offers plug-and-play functionality.

VI. System Integration and Configuration Guide

Hardware Connection Steps

Connect Pump and Controller: Directly insert the motor connector of the micro diaphragm pump into the dedicated output socket of the TS-CC speed controller.
Power Connection: Connect a 12/24V DC power supply to the TS-CC speed controller.
Bus Connection:
- Use shielded twisted pair cable to connect the “A” and “B” terminals of all TS-CC speed controllers and other devices on the bus.
- Connect 120Ω termination resistors in parallel between the “A” and “B” terminals at the beginning and end of the bus.
Address Setting: Set a unique Modbus station address (1-247) for each node using the TS-CC speed controller PC software.

Software Configuration and Programming Example

Master Configuration: Configure Modbus master parameters (baud rate, data bits, stop bits, parity) in the PLC or PC software. These must match the default settings of the TS-CC speed controller (e.g., 19200, 8, 1, None).
Register Mapping:
- Control Register (Holding Register, Address 0x0001): Write 500-3000, corresponding to speed setting 500-3000 RPM.
- Status Register (Input Register, Address 0x0002): Read 500-3000, representing actual speed in RPM.
Programming Example (Pseudocode Logic Fragment): // Set pump speed at station address 01 to 2000 RPM MODBUS_WRITE: Slave_ID := 1; Function := 0x06; // Write single holding register Address := 0x0001; // Corresponds to register 0x0001 Data := 2000; // 2000 RPM speed Trigger := Start_Signal; // Read pump start/stop status at station address MODBUS_READ: Slave_ID := 1; Function := 0x04; // Read input registers Address := 0x0000; // Start from 0x0000 Length := 1; // Read 1 register Trigger := Periodic_Timer;

VII. Application Example and Effect Analysis

Scenario: Intelligent Chemical Agent Quantitative Dosing System

In the pH neutralization stage of an environmental water treatment plant, precise control over the dosing amounts of acid and alkali agents is required based on influent flow rate and real-time pH value.

Traditional Solution: Using two independently regulated micro diaphragm pumps with analog speed controllers. pH meter and flow meter signals are connected to the PLC, which controls pump speeds via analog outputs (0-10V). This requires extensive analog signal wiring, is susceptible to interference, and cannot remotely obtain pump status.

After Adopting This Solution:

Equipment: 2 S33 series corrosion-resistant diaphragm pumps + 2 TS-CC speed controllers + 1 Modbus pH meter + 1 Modbus flow meter.
Integration: All devices connected to the PLC via a single RS-485 bus.
Control Logic: The PLC calculates in real-time based on flow and pH feedback and adjusts the dosing speed of the two pumps via Modbus commands.

Implementation Effect Comparison:

Comparison Item	Traditional Solution	This Solution
Control Cabinet Wiring	Complex, mixed analog/digital lines	Extremely simple, only power lines and bus
Debugging Time	Relatively long (requires analog calibration)	Reduced by approximately 60%
System Cost	Higher (analog modules,many cables)	Reduced by approximately 25%
Status Monitoring	Only basic start/stop	Comprehensive (speed, current, fault)
Maintenance Convenience	Difficult fault location	Bus diagnostics, quick node location
Scalability	Adding equipment requires rewiring	Easy expansion by connecting to the bus

Customer Feedback: The system operates stably, dosing accuracy is significantly improved, and daily maintenance workload is greatly reduced.

VIII. Summary of Advantages and Product Value

Core Value of TS-CC Speed Controller:

Simplify Complexity: Transforms the traditional complex “power + signal” control mode into a minimalist “power + network” mode.
Cost Optimization: Significantly saves costs related to PLC modules, cables, and installation labor, reducing the Total Cost of Ownership (TCO).
Information Transparency: Enables data acquisition at the actuator level, providing a data foundation for equipment health management and predictive maintenance.
High Reliability: Industrial-grade design and digital communication offer strong anti-interference capability, enhancing overall system reliability.

Advantages of Matching Micro Diaphragm Pumps:

One-Stop Solution: Provides a complete product chain from the pump body to the bus interface, ensuring optimal compatibility and performance.
Enhanced Product Competitiveness: Helps equipment manufacturers (OEMs) rapidly develop more advanced and competitive intelligent fluid handling equipment.

IX. Conclusion and Recommendation

Integration and networking are irreversible trends in industrial automation. By adopting a control architecture based on the Modbus bus, combined with our TS-CC intelligent speed controller and high-performance micro diaphragm pumps, customers can efficiently and economically build modern fluid control systems.

We sincerely recommend adopting this solution for new project designs or upgrades of existing equipment to reap the multiple benefits of simplified engineering, enhanced performance, and reduced long-term operational costs. Our technical team can provide full-process support from selection and solution design to commissioning assistance.