Communication Protocols

Communicating with your instrument

Alicat devices are compatible with a variety of analog, serial, or industrial communication protocols for easy data collection and analysis. Options include:

  • Analog (4-20 mA, 0-10 Vdc, 0-5 Vdc, or 1-5 Vdc)
  • ASCII and Modbus RTU over RS-232
  • ASCII and Modbus RTU over RS-485
  • Profibus
  • DeviceNet
  • EtherNet/IP
  • Modbus TCP/IP
  • EtherCAT
  • Bluetooth

Most devices use 0-5 Vdc analog and ASCII and Modbus RTU over RS-232 by default. Connectors and pinouts are customizable.

Serial Interfaces (RS-232 and RS-485)

Alicat instruments ordered without an industrial protocol include digital serial communications for easy transfer of flow data to a computer or PLC. Like RS-485, Alicat’s implementation of RS-232 is multi-drop and can accommodate up to 26 different instruments on one network.

Serial interface options:

  • RS-232 (default) multi-drop serial protocol
  • RS-485 multi-drop serial protocol

Additional options:

  • Preset Unit ID (ID:) sets the unit identifier number for your instrument (default Unit ID is A).
  • Preset Baud Rate (BAUD:) sets the baud rate for your instrument (default is 19200).
  • Preset Streaming Rate (SR:) sets the serial streaming rate for your instrument (default is 50 ms).
  • Preset Streaming Mode (STR) presets your instrument to ship to you in streaming mode instead of polling mode.

 

Analog Signals

Most Alicat instruments come with analog outputs; flow and pressure controllers also include analog input signals. Many instruments can carry a secondary analog output signal, which is entirely independent of the first. Analog signals are called out in the adder code portion of Alicat part numbers.

Available analog output signal types:

  • 0-5 Vdc (default) for mass flow (5M), volumetric flow (5V), pressure (5P) or temperature (5T)
  • 1-5 Vdc for mass flow (1M), volumetric flow (1V), pressure (1P) or temperature (1T)
  • 0-10 Vdc for mass flow (10M), volumetric flow (10V), pressure (10P) or temperature (10T)
  • 4-20 mA for mass flow (CM), volumetric flow (CV), pressure (CP) or temperature (CT)

Secondary analog outputs can be used to transmit data for the same flow parameter to a second receiver, or you can use it to send data for a second parameter altogether. It is not necessary for the secondary analog output signal type to agree with the primary output signal type (e.g., 0-5 volts). Secondary analog output signals are indicated with a “2” placed in the middle of the above adder codes (e.g., 52M, 12V, 102T or C2P).

Available analog input signal types:

  • 0-5 Vdc (default) setpoint input (5IN)
  • 1-5 Vdc setpoint input (1IN)
  • 0-10 Vdc setpoint input (10IN)
  • 4-20 mA setpoint input (CIN)

 

Alicat PROFIBUS DP-V0 compatible slave devices are suitable for use on a PROFIBUS DP network.

Connector options:

  • Female 9-pin D-sub DP and female 4-pin M8A power connectors on top

Additional options:

  • Power over PROFIBUS (POP) routes power through the top DP connector instead of the side-mounted one
  • Preset Unit ID sets the unit identifier numbers for your instruments at the factory (default Unit ID is 125)

Resources:

For instruments built after* July 12, 2020:

For instruments built before July 12, 2020:

*Customers with the GSD file for instruments built prior to July 12, 2020 file may continue using it with new units if your system is already configured.

Use the Modbus application layer messaging protocol to format data for communications among industrial devices.

Communication options:

  • Modbus-RTU over RS-232
  • Modbus-RTU over RS-485

Connector options:

  • 8-pin mini-DIN (default)
  • 9-pin or 15-pin D-Sub
  • RJ46

Resources:

  • Modbus Poll Data Registers – MBP file – This loads the configuration requirements required to read the available data registers on any Modbus-equipped Alicat device and is useful for troubleshooting and viewing the required Modbus data settings.

PLCs running the Modbus industrial automation protocol over Ethernet cable can connect with Alicat instruments using the Modbus TCP/IP protocol option.

Communication options:

  • 10BaseT and 100BaseT Ethernet communication

Connector options:

  • Two RJ45 connectors on top with green and amber status lights

The EtherCAT protocol uses ethernet cables to achieve rapid data transfer rates for hundreds or thousands of devices on a single network.

Communication options:

  • 10BaseT and 100BaseT Ethernet communication

Connection options:

  • Two RJ45 connectors on top with green and amber status lights

Resources:

ethernetip protocol logo

Automate your flow and pressure control system through an Ethernet cable connection. Alicat is a member of ODVA, the EtherNet/IP certification body, and our EtherNet/IP instruments are ODVA CONFORMANT™.

Communication options:

  • 10BaseT and 100BaseT Ethernet communication

Connector options:

  • Two RJ45 connectors on top with green and amber status lights

Resources:

device net protocol logo

Alicat is a member of ODVA, the DeviceNet certification body, and our DeviceNet instruments are ODVA CONFORMANT™.

Connector options:

  • Male 5-pin DeviceNet connector on top and male 9-pin D-sub connector on the side

Resources:

 

 

 

Alicat offers Bluetooth on portable mass flow meters and portable liquid meters.

Control your devices and read data in real-time with the Alicat Connect app. Portable devices equipped with Bluetooth also include serial communication over micro-USB.

Connector options:

  • Bluetooth antenna with threaded SMA connector