RS232 / RS485 Pressure Instruments
Last Updated: February 12, 2025
Description
RS232 and RS485 pressure instruments are devices that utilize serial communication protocols to transmit pressure data. These instruments are designed to send data one bit at a time, allowing for precise and reliable data transmission over various distances. They are commonly used in environments where digital communication is essential for monitoring and controlling pressure levels.
Working Principle
RS232 and RS485 pressure instruments operate by converting pressure measurements into digital signals that can be transmitted over a serial communication line. RS232 is typically used for short-range, point-to-point communication, while RS485 supports longer distances and can connect multiple devices on a single network. The RS485 protocol allows for up to 32 sensors to communicate with a supervisory computer, and with additional hardware, this can be extended to 256 sensors. This capability makes RS485 particularly useful in industrial settings where multiple pressure points need to be monitored simultaneously.
Applications
RS232 and RS485 pressure instruments are used in a variety of applications. For example, RS232 is often employed in data logging systems for diesel engine emissions control, where it interfaces with modems to provide remote monitoring capabilities. RS485 is advantageous in industrial environments where multiple sensors need to be networked over long distances, such as in factory automation systems or large-scale environmental monitoring setups.
Advantages over other Pressure Instruments
One of the main advantages of RS485 over RS232 is its ability to handle longer distances and multiple devices on a single network. RS485 can transmit data over distances up to 1,200 meters, making it suitable for large industrial sites. Additionally, RS485's capability to connect multiple sensors reduces the need for extensive wiring, which can lower installation costs and complexity.
Limitations
RS232 is limited by its short-range communication capability and is typically used for point-to-point connections. It is not suitable for applications requiring long-distance data transmission or networking multiple devices. RS485, while more versatile, requires additional hardware for signal repeaters if more than 32 devices need to be connected, which can increase system complexity and cost.
Considerations
When selecting RS232 or RS485 pressure instruments, several factors should be considered. Initial costs can vary depending on the complexity of the network and the number of devices. Operating expenses may include maintenance of the communication network and any additional hardware required for RS485 systems. Durability and accuracy are generally high for these instruments, but regular calibration and maintenance are necessary to ensure long-term performance. Replacement and maintenance costs should also be factored into the overall budget, especially in large-scale installations where multiple sensors are used.
from Orange Research, Inc.
Diaphragm Sensors with Explosion-Proof Enclosures. Hazardous location differential pressure gauges measure the pressure difference between two points. Acting in the place of two pressure gauges, these units allow for one simple reading on an easy-to-read scale. Popular in filtration, flow and level... [See More]
- Signal Output: Analog Voltage; Analog Current; RS232/485
- Sensor Technology: Mechanical Deflection
- Device Category: Instrument or Meter
- Pressure Measurement: Differential
from Vaisala
For Harsh Environments. Excellent solution for outdoor installations. Operates in a wide temperature range. The housing provides IP65 (NEMA4) compliant protection against sprayed water. Features • 500 ... 1100 hPa or 50 .... 1100 hPa pressure ranges with serial output •... [See More]
- Signal Output: Analog Voltage; Analog Current; RS232/485
- Sensor Technology: Vaisala BAROCAP sensor, a silicon capacitive absolute pressure sensor
- Device Category: Instrument or Meter
- Pressure Measurement: Absolute
from Setra Systems
This highly accurate (0.02% FS) self-contained instrument has a 6-digit LCD display and a numeric keypad for access to engineering unit conversions. In addition, an RS-232 communications port is available for computer access. Features: +/-0.02% Full Scaleb Accuracy. High Resolution 6 Digit LCD... [See More]
- Signal Output: RS232/485
- Sensor Technology: Variable Capacitance
- Device Category: Instrument or Meter
- Pressure Measurement: Gauge
from Edwards Vacuum
The TIC Instrument Controller provides compact control with a large, clear graphical display, an intuitive user interface and serial communications. The supplied Windows ™-based PC program provides full remote setup, control and data logging functions via the RS232 interface. Three TIC... [See More]
- Signal Output: RS232/485
- Sensor Technology: Various
- Device Category: Controller
- Pressure Measurement: Gauge; Vacuum
from VACUUBRAND, Inc.
The CVC 3000 controller manages vacuum processes by controlling vacuum pumps, vacuumvalves, coolant valves and accessories, and is self-configuring. The illuminated graphical display with clear text menus (14 languages) and the jog wheel make its handling nearly self-explanatory. Depending on the... [See More]
- Signal Output: RS232/485
- Sensor Technology: Variable Capacitance
- Device Category: Instrument or Meter; Recorder or Totalizer; Controller
- Pressure Measurement: Absolute; Vacuum
from Crystal Engineering Corporation
Rugged & accurate pressure gauge, NEMA4 rated, RS232 port [See More]
- Signal Output: RS232/485
- Sensor Technology: Silicon Sensor
- Device Category: Instrument or Meter
- Pressure Measurement: Absolute; Gauge; Vacuum
from Bronkhorst USA
EL-PRESS Metal Sealed Pressure Meters / Controllers. Metal Seal Pressure Meters and Controllers of Bronkhorst High-Tech are characterised by their unique, patented metal-to-metal seal construction with excellent resealing capability. Furthermore they distinguish themselves by a high surface quality... [See More]
- Signal Output: Analog Voltage; Analog Current; RS232/485; PROFIBUS® (optional feature); DeviceNet (optional feature); Modbus, EtherCAT, FLOW-BUS
- Sensor Technology: Piezoelectric
- Device Category: Instrument or Meter; Controller (optional feature)
- Pressure Measurement: Absolute; Gauge
from Uehling Instrument Company
Digital Tank-O-Meters ® accurately measure tank contents regardless of the tank location in relation to the Digital Display. They are a natural extension of Uehling's well known and time proven line (since 1896) of Tank-O-Meter ® gauge products. Systems are also available as a retrofit... [See More]
- Signal Output: Analog Voltage; Analog Current; RS232/485; Switch
- Sensor Technology: Air Bubbler
- Device Category: Instrument or Meter
- Pressure Measurement: Gauge; Vacuum
from REED-Direct
Large LCD readout with contrast adjustment. Zero function for offset measurements. Data Hold and Min/Max recall. Auto power off. RS232 serial interface. Sampling Time: 0.8 second. Hard carrying case included. SPECIFICATIONS: Function / Range / Resolution / Accuracy. mbar / ±2000 / 1 /... [See More]
- Signal Output: RS232/485
- Pressure Measurement: Differential; Gauge; Negative Pressure
- Device Category: Instrument or Meter
- Display Type: Digital Numerical Display
from Traceable® Products
Manometer displays gauge and differential pressure/vacuum in eleven different units. Response time is 0.5 second. Simple hose fittings on the unit permit using hose/tubing with inside diameters from 1/16 to 3/16 inches. Large 5/8-inch-high digits are visible from six feet. At the touch of a button... [See More]
- Signal Output: RS232/485
- Pressure Measurement: Gauge; Vacuum
- Device Category: Instrument or Meter
- Material: Gas
from Setra Systems
Has the same functionality as the Model 370, but does not include the LCD display or numeric keypad. Used as the barometric standard in Automated Surface Observation Systems (worldwide) where accuracy, stability and versatility are essential. Features: +/-0.02% Full Scaleb Accuracy. Bidirectional... [See More]
- Signal Output: RS232/485
- Sensor Technology: Variable Capacitance
- Device Category: Instrument or Meter
- Pressure Measurement: Gauge
from Edwards Vacuum
The TIC Instrument Controller provides compact control with a large, clear graphical display, an intuitive user interface and serial communications. The supplied Windows ™-based PC program provides full remote setup, control and data logging functions via the RS232 interface. Up to six Edwards... [See More]
- Signal Output: RS232/485
- Sensor Technology: Various
- Device Category: Controller
- Pressure Measurement: Gauge; Vacuum
from VACUUBRAND, Inc.
The DCP 3000 is an electronic vacuum gauge for rough and fine vacuum. Simultaneous connection of up to eight external vacuum sensors (four VSK 3000 and four VSP 3000) allows flexible measuring on the spot. A large illuminated display shows the measuring values of all sensors by a simple turn of a... [See More]
- Signal Output: RS232/485
- Sensor Technology: Variable Capacitance
- Device Category: Instrument or Meter; Recorder or Totalizer (optional feature)
- Pressure Measurement: Absolute; Vacuum
from Bronkhorst USA
EL-PRESS Digital Electronic Pressure Meters / Controllers. The EL-PRESS series digital electronic pressure transducers and controllers for gases and liquids have a well-proven compact thru-flow design. The instruments include a diaphragm type piezo-resistive pressure sensor for pressure... [See More]
- Signal Output: Analog Voltage; Analog Current; RS232/485; PROFIBUS® (optional feature); DeviceNet (optional feature); Modbus, EtherCAT, FLOW-BUS
- Sensor Technology: Piezoelectric
- Device Category: Instrument or Meter; Controller (optional feature)
- Pressure Measurement: Absolute; Gauge
from Uehling Instrument Company
Type "U" Ultrasonic Digital Tank-O-Meters ® are provided with (2) user programmable setpoint relays. (For alarms, pump/valve on/off, maintaining levels) and an analog output (4-20 mA, 0-10VDC or 0 to 5 VDC). Serial Outputs are also available. [See More]
- Signal Output: Analog Voltage; Analog Current; RS232/485
- Sensor Technology: Ultrasonic
- Device Category: Instrument or Meter
- Pressure Measurement: Gauge
from REED-Direct
Dual LCD readouts with backlighting. Min/Max/Avg recording with time stamp. Data hold freezes the displayed reading. Push button zero adjust and offset readings. Low battery indication with auto power off. RS232 serial port. Includes RS232 cable, tubing, hard carrying case and batteries. [See More]
- Signal Output: RS232/485
- Pressure Measurement: Gauge
- Device Category: Instrument or Meter
- Display Type: Digital Numerical Display
from Traceable® Products
Displays answer in eight different units. Meter is accurate to 1% full-scale plus 1 digit. Jumbo-size digits are 3/8-inch-high. Serial RS-232 output allows it to be connected to a computer or data logger for monitoring and keeping results. To assure accuracy an individually serial-numbered Traceable... [See More]
- Signal Output: RS232/485
- Pressure Measurement: Gauge; Vacuum
- Device Category: Instrument or Meter
- Material: Liquid; Gas
from Edwards Vacuum
The TIC Instrument Controller provides compact control with a large, clear graphical display, an intuitive user interface and serial communications. The supplied Windows ™-based PC program provides full remote setup, control and data logging functions via the RS232 interface. Up to six Edwards... [See More]
- Signal Output: RS232/485
- Sensor Technology: Various
- Device Category: Controller
- Pressure Measurement: Gauge; Vacuum
from Bronkhorst USA
EL-PRESS Digital Electronic Pressure Meters / Controllers. The EL-PRESS series digital electronic pressure transducers and controllers for gases and liquids have a well-proven compact thru-flow design. The instruments include a diaphragm type piezo-resistive pressure sensor for pressure... [See More]
- Signal Output: Analog Voltage; Analog Current; RS232/485; PROFIBUS® (optional feature); DeviceNet (optional feature); Modbus, EtherCAT, FLOW-BUS
- Sensor Technology: Piezoelectric
- Device Category: Instrument or Meter; Controller (optional feature)
- Pressure Measurement: Differential
from REED-Direct
Push-button transducer selection. Zero function for offset correction. Data Hold and Min/Max recall. Auto power off. RS232 serial interface. SPECIFICATIONS: Range / 30psi / 75psi / 150psi / 300psi / 725psi / 1450psi. mbar / 0.002-2 / 0.005-5 / 0.1-10 / 0.2-20 / 0.05-50 / 0.1-100. psi / 0.02-29 /... [See More]
- Signal Output: RS232/485
- Pressure Measurement: Gauge
- Device Category: Instrument or Meter
- Display Type: Digital Numerical Display
from Bronkhorst USA
EL-PRESS Digital Electronic Pressure Meters / Controllers. The EL-PRESS series digital electronic pressure transducers and controllers for gases and liquids have a well-proven compact thru-flow design. The instruments include a diaphragm type piezo-resistive pressure sensor for pressure... [See More]
- Signal Output: Analog Voltage; Analog Current; RS232/485; PROFIBUS® (optional feature); DeviceNet (optional feature); Modbus, EtherCAT, FLOW-BUS
- Sensor Technology: Piezoelectric
- Device Category: Instrument or Meter; Controller
- Pressure Measurement: Absolute; Gauge
from Bronkhorst USA
EL-PRESS Digital Electronic Pressure Meters / Controllers. The EL-PRESS series digital electronic pressure transducers and controllers for gases and liquids have a well-proven compact thru-flow design. The instruments include a diaphragm type piezo-resistive pressure sensor for pressure... [See More]
- Signal Output: Analog Voltage; Analog Current; RS232/485; PROFIBUS® (optional feature); DeviceNet (optional feature); Modbus, EtherCAT, FLOW-BUS
- Sensor Technology: Piezoelectric
- Device Category: Instrument or Meter; Controller
- Pressure Measurement: Absolute; Gauge
from Bronkhorst USA
IN-PRESS Industrial style Digital Pressure Meters / Controllers. The IN-PRESS series digital electronic pressure transducers and controllers for gases and liquids are equipped with a rugged, 'industrial style' (IP65) pc-board housing for use in industrial environments. The instruments have a... [See More]
- Signal Output: Analog Voltage; Analog Current; RS232/485; PROFIBUS® (optional feature); DeviceNet (optional feature); Modbus, FLOW-BUS
- Sensor Technology: Semiconductor Piezoresistive
- Device Category: Instrument or Meter; Controller (optional feature)
- Pressure Measurement: Absolute; Gauge
from Bronkhorst USA
IN-PRESS Industrial style Digital Pressure Meters / Controllers. The IN-PRESS series digital electronic pressure transducers and controllers for gases and liquids are equipped with a rugged, 'industrial style' (IP65) pc-board housing for use in industrial environments. The instruments have a... [See More]
- Signal Output: Analog Voltage; Analog Current; RS232/485; PROFIBUS® (optional feature); DeviceNet (optional feature); Modbus, FLOW-BUS
- Sensor Technology: Semiconductor Piezoresistive
- Device Category: Instrument or Meter; Controller
- Pressure Measurement: Absolute; Gauge
from Bronkhorst USA
IQ+FLOW ® Chip-sensor based Pressure Meters / Controllers. Equipment manufacturers are looking for compact solutions to monitor or control the gas flow or pressure in their system. Previously, conventional Mass Flow and Pressure Meters and Controllers have needed a footprint of 1.5", as for... [See More]
- Signal Output: Analog Voltage; Analog Current; RS232/485; Modbus, Flowbus
- Sensor Technology: Semiconductor Piezoresistive
- Device Category: Instrument or Meter; Controller
- Pressure Measurement: Absolute; Gauge