Advantages, Disadvantages and Application Cases of Pressure Gauge with RS485 MODBUS Communication

Sep 28, 2026

Digital pressure gauges commonly seen in the current industrial control market feature display, digital switch output and analog output. Readers of this article are presumed to be industry professionals, so we will not elaborate on these three functions. The following comparison focuses on our RS485-based MODBUS communication function versus switch or analog output.

NOTE: Default configuration of our MODBUS pressure gauge: RTU mode, Data Bit (8bit), Start Bit (1bit), Stop Bit (1bit), Parity (None), Baud Rate (19200)

No.	Comparison Item	MODBUS	Switch	Short
1	Transmission Distance	Long, ex-factory test up to 30m	Relatively long	Short
2	Anti-interference Performance	RS485 and CRC check ensure data reliability via hardware and software respectively.	Excellent.	Poor
3	Access Port	Up to 35 pieces pressure gauges can be connected via 2 ports	One port per switch	One port per analog signal
4	Data Direction	Bidirectional communication, readable and writable	Unidirectional	Unidirectional
5	Implementation Difficulty	Relatively difficult, requires basic PLC programming knowledge	Simple	Simple
6	Hardware Cost	Limited analog input ports on PLC; expansion ports may be required	Limited analog input ports on PLC; expansion ports may be required	Limited analog input ports on PLC; expansion ports may be required

Our Application Cases

1. Foxcon

Multiple sets of our MODBUS pressure gauges together with one MODBUS-to-WIFI module are adopted for data acquisition in digital factories. It transmits air pressure values of machine tools in the workshop to the data collector installed at the top of the workshop at fixed intervals for pressure monitoring and data logging.

MODBUS pressure gauges were selected for reliable data performance. Multiple pressure gauges can share a single MODBUS-to-WIFI module, eliminating the need for additional conversion modules."

2. Alpha Automation

Our MODBUS pressure gauges are deployed on production and test equipment for new energy vehicle batteries. They collect pressure data across different working ranges and upload readings to the main PLC.

Multiple pressure gauges move together with robotic arms. Data is transmitted via contact points connected to the stationary main PLC. Limited mechanical structure leaves no room for extra ADC contact points. Multiple pressure gauges share only 2 contacts with other MODBUS devices to complete data acquisition."

3. Langde Automation

Our MODBUS pressure gauges are installed on on-site automation equipment to collect pressure values on various automated arms and upload data to the main PLC.

The working site features harsh conditions and heavy electrical interference. Some gauges require very long wiring distances. Switch + analog output cannot operate stably under such circumstances. MODBUS pressure gauges perfectly solve this problem.

From the above three typical cases, RS485 MODBUS pressure gauges are mainly suitable for the following scenarios:

1. Applications requiring remote reading of on-site pressure data;

2. Sites with poor electromagnetic environment and strong electrical interference;

3. Installations with long cable runs;

4. Equipment systems integrating multiple pressure gauges;

5. Systems with limited ports, no available ADC ports or where customers prefer to avoid adding ADC expansion modules;

6. Projects demanding high data reliability.