Modbus Rtu Rs485

Modbus RTU es un protocolo serie abierto (RS-232 o RS-485) basado en una arquitectura maestro/esclavo o cliente/servidor. El protocolo interconecta los equipos de campo, como son los sensores, los actuadores y los controladores y se usa ampliamente en la. This document describes the RS-485 cabling requirements for Modbus RTU and BACnet MSTP. 1.2 INTRODUCTION The signal lines of RS-485 networks are differential twisted pairs. This allows for fast, long length networks up to 4000ft, but conditions have to near ideal for successful networking at these extremes.

The DCT 531 digital pressure sensor has a Modbus RTU RS485 serial communications protocol interface for transmitting pressure readings over a digital sensor network. A variety of electrical & process connection combinations are possible, with a choice of fixed pressure ranges from 0-100 mbar up to 0-400 bar gauge/absolute.

A RS 485 serial interface will allow you to daisy chain multiple sensors on one communication loop, which eliminates the need to send a separate signal wire from each sensor to data acquisition instrumentation.

Product Help

Detecting 0.0006 bar change around 0.3 bar

We have an operational pressure of 0.3 bar, and we want to detect a pressure change of 0.006 bar, so ideally we want at least 4 decimal places resolution?

The 0.1% accuracy version of the DCT 531 utilises a 16 bit ADC, so you should be able to detect in the order of 0.002% full scale. For a pressure range of 0.4 bar range this would be equivalent to 0.000008 bar, which would comfortably exceed your resolution requirements.

Temperature measurement

Is it possible to also measure temperature with the DCT 531?

Yes it is, but not as standard, to measure pressure and temperature you would need a version called the DCT 531i. This comes with an extra set of Modbus RTU input registers, holding registers, and enumeration for reading temperature and selecting temperature units

Custom Modbus configuration

Is it possible to request custom Modbus settings for address and other settings?

Rs485

Yes a specific Modbus settings can be configured by the factory if specified when ordered.

High vacuum resistance

What does the vacuum resistance spec of unlimited vacuum resistance for pressure greater than 1 bar mean?

This refers to high vacuum resistance only, so it is not advisable to expose ranges below 1 bar to a high vacuum since this likely to alter the performance of the sensor, and ranges of 1 bar or greater are not affected by exposure to a high vacuum.

Modbus RTU register values

What are the register values for sending commands to the Modbus RTU communications?

The explicit register description is shown in the table below:

Modbus RTU configuration

I’d like to check the compatibility of the Modbus connection and would appreciate if you could show the configuration documentation, in particular I’m interested in the facilities for changing network id, baud rate and parity?

Modbus Rtu Protocol Pdf

Click on the image below to view the Modbus RTU configuration for the BD Sensors DCT 531:

Irrigation water control

We are looking for a 2-wire pressure transducer in the 0-30psig range with a Modbus RS485 output. Our industry is irrigation water control.

We would suggest the following DCT531 specification:

  • SKU ID: s1-dct531-0002
  • Part No: DC7-2501-L5-2-N11-N00-1-000
  • Pressure Range: 0 – 2.5 bar g
  • Output: RS 485
  • Supply Voltage: 9 – 32V dc
  • Electrical Connection: Male plug M12x1 (5-pin) / metal
  • Process Connection: 1/2 NPT male
  • Process Connection Material: Stainless Steel 316L
  • Seal Material: FKM
  • Diaphragm Material: Stainless Steel 316L
  • Accuracy (NL&H): 0.25% FSO IEC 60770
  • IP Rating: 65
  • Media Temperature: -25 to +125°C
  • Operating Temperature: -25 to +85°C
  • Special Options: None
  • Approvals: None

10 bar range with cable connection

We need a sensor to measure up to 10 bar on air for a development project. We have a system capable of using a Modbus RTU serial interface for transmitting the data. A 12v supply is available and we would need a direct cable connection to the probe?

Modbus Rtu Rs485 Gas Detector

485

The following spec would meet all your requirements.

  • SKU ID: s1-dct531-0001
  • Part No: DC7-1002-L5-2-N11-100-1-000
  • Pressure Range: 0 – 10 Bar G
  • Output: RS 485
  • Supply Voltage: 9 – 32V dc
  • Electrical Connection: Male plug M12x1 (5-pin) / metal
  • Process Connection: G 1/2″ DIN 3852
  • Process Connection Material: Stainless Steel 316L
  • Seal Material: FKM
  • Diaphragm Material: Stainless Steel 316L
  • Accuracy (NL&H): 0.25% FSO IEC 60770
  • IP Rating: 65
  • Media Temperature: -25 to +125°C
  • Operating Temperature: -25 to +85°C
  • Special Options: None
  • Approvals: None

Part Numbers

DC8-1002-L5-3-TA0-N40-1-000

10 bar absolute range Modbus RTU pressure sensor for installing with a 1/4 NPT male pressure fitting and a 2 metre length of cable.

  • SKU ID: s1-dct531-0005
  • Part No: DC8-1002-L5-2-N11-N40-1-000
  • Pressure Range: 0 – 10 bar absolute
  • Output: RS 485 Modbus RTU
  • Supply Voltage: 9 – 32V dc
  • Electrical Connection: Male plug M12x1 (5-pin)
  • Process Connection: 1/4 NPT male
  • Process Connection Material: Stainless Steel 316L
  • Seal Material: FKM
  • Diaphragm Material: Stainless Steel 316L
  • Accuracy (NL&H): 0.25% FSO IEC 60770
  • IP Rating: 65
  • Media Temperature: -25 to +125°C
  • Operating Temperature: -25 to +85°C
  • Special Options: None
  • Approvals: None

DC7-1602-L5-3-M13-300-1-000

16 bar gauge RS485 Modbus RTU digital interface pressure sensor.

  • SKU ID: s1-dct531-0003
  • Part No: DC7-1602-L5-2-N11-300-1-000
  • Pressure Range: 0 – 16 Bar G
  • Output: RS 485
  • Supply Voltage: 9 – 32V dc
  • Electrical Connection: Male plug M12x1 (5-pin) / metal (excludes mating connector)
  • Process Connection: G1/4 DIN 3852 male
  • Process Connection Material: Stainless Steel 316L
  • Seal Material: FKM
  • Diaphragm Material: Stainless Steel 316L
  • Accuracy (NL&H): 0.25% FSO IEC 60770
  • IP Rating: 65
  • Media Temperature: -25 to +125°C
  • Operating Temperature: -25 to +85°C
  • Special Options: None
  • Approvals: None

DC7-4002-L5-3-M13-300-1-000

40 bar gauge RS485 Modbus RTU digital interface pressure sensor.

  • SKU ID: s1-dct531-0004
  • Part No: DC7-4002-L5-2-N11-300-1-000
  • Pressure Range: 0 – 40 Bar G
  • Output: RS 485
  • Supply Voltage: 9 – 32V dc
  • Electrical Connection: Male plug M12x1 (5-pin) / metal (excludes mating connector)
  • Process Connection: G1/4 DIN 3852 male
  • Process Connection Material: Stainless Steel 316L
  • Seal Material: FKM
  • Diaphragm Material: Stainless Steel 316L
  • Accuracy (NL&H): 0.25% FSO IEC 60770
  • IP Rating: 65
  • Media Temperature: -25 to +125°C
  • Operating Temperature: -25 to +85°C
  • Special Options: None
  • Approvals: None

Related Documents

Specification data sheet


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