Engee documentation

VISA Software Management

This page contains all the available VISA software management functions in Engee.

To work with the VISA software management functions in Engee, follow the instructions provided in article. After that, perform:

using Main.EngeeDeviceManager.Devices.VISA

Next, you need to create a VISA object that will be used to interact with measuring devices.:

visa = VISA.Visa()

Methods VISA

visa.close_instrument(port)

Releases the bus for the device connected via the VISA specification.

Arguments

port::String: the port of the device connected via the VISA specification. You can get it using the function visa.get_ports().

Examples

visa = VISA.Visa()
visa.create_session("@py")
ports = visa.get_ports().data
port = last(ports)
visa.create_instrument(port)
visa.close_instrument(port)
visa.close_session()

Closes the VISA session.

Arguments

Missing (the method is called from the VISA object).

Examples

visa = VISA.Visa()
visa.create_session("@py")
ports = visa.get_ports().data
port = last(ports)
visa.close_session()
visa.create_instrument(port)
visa.create_instrument(port, settings)

Creates an instance of the device connected on the specified port.

Arguments

  • port::String: the port of the device connected via the VISA specification. You can get it using the function visa.get_ports().

  • settings::PortSettings: connection parameters. If the field is set to nothing, then the default value of the driver/device is used.

Structure PortSettings

Base.@kwdef mutable struct PortSettings
    baud_rate::Union{Int64, Nothing} = nothing
    chunk_size::Union{Int64, Nothing} = nothing
    write_termination::Union{String, Nothing} = nothing
    read_terminator::Union{String, Nothing} = nothing
    CR::Union{String, Nothing} = nothing
    LF::Union{String, Nothing} = nothing
end

here:

  • baud_rate: the transmission rate via the COM interface.

  • chunk_size: the size of the read block (chunk). (Some serial devices do not support large chunk values. If problems occur, decrease the parameter value. chunk_size).

  • write_termination: the end-of-byte sequence completion character(s) for writing, for example "\r", \n, \r\n.

  • read_terminator: the end-of-byte sequence completion character(s) for reading, for example "\n" or \r\n.

  • CR: carriage return control symbol ("\r") when writing/reading streams.

  • LF: line feed control character ("\n") when writing/reading streams.

Examples

# Classic device instance creation
visa = VISA.Visa()
visa.create_session("@py")
ports = visa.get_ports().data
port = last(ports)
visa.create_instrument(port)

# Creating an instance with PortSettings parameters
visa = VISA.Visa()
visa.create_session("@py")
ports = visa.get_ports().data
port = last(ports)

visa.create_instrument(port, VISA.PortSettings(
  baud_rate = 115200,
  chunk_size = 256,
  write_termination = "\r\n",
  read_terminator = "\n",
  CR = "\r",
  LF = "\n",
))
visa.create_session(backend)

Creates a session for working with VISA.

Arguments

backend::String: hardware implementation of the VISA specification, for example, "@py" or "@ni".

Examples

visa = VISA.Visa()
visa.create_session("@py")
visa.flush(port, flush_type)

Clears the I/O buffers of the device.

Arguments

  • port::String: the port of the device connected via the VISA specification. You can get it using the function visa.get_ports().

  • flush_type::String: type of cleaning. For example: "flush_write_buffer" or "flush_transmit_buffer".

Examples

visa = VISA.Visa()
visa.create_session("@py")
ports = visa.get_ports().data
port = last(ports)
visa.create_instrument(port)
visa.flush(port, "flush_write_buffer")
visa.get_ports()

Retrieves the list of available physical ports.

Arguments

Missing (the method is called from the VISA object).

Examples

visa = VISA.Visa()
visa.create_session("@py")
ports = visa.get_ports().data
visa.read(port, termination)

Reads data from the device.

Arguments

  • port::String: the port of the device connected via the VISA specification. You can get it using the function visa.get_ports().

  • termination::String: A device-specific read completion symbol. If it is not defined, then it should be left empty. "".

Examples

visa = VISA.Visa()
visa.create_session("@py")
ports = visa.get_ports().data
port = last(ports)
read_result = visa.read(port, "").data
visa.readbinblock(port, size)

Reads binary data from the device.

Arguments

  • port::String: the port of the device connected via the VISA specification. You can get it using the function visa.get_ports().

  • size::Int64: the size of the buffer for reading bytes, for example: 8.

Examples

visa = VISA.Visa()
visa.create_session("@py")
ports = visa.get_ports().data
port = last(ports)
bytes = visa.readbinblock(port, 8).data
visa.visatrigger(port)

Sends interrupt commands to the device.

Arguments

port::String: the port of the device connected via the VISA specification. You can get it using the function visa.get_ports().

Examples

visa = VISA.Visa()
visa.create_session("@py")
ports = visa.get_ports().data
port = last(ports)
visa.visatrigger(port)
visa.write(port, message, termination)

Writes messages to the device.

Arguments

  • port::String: the port of the device connected via the VISA specification. You can get it using the function visa.get_ports(visa::Any).

  • message::String: message with the SCPI command. For example: "RST;:SYSTEM:LOCK OFF" to reset the settings.

  • termination::String: A device-specific recording completion symbol. If it is not defined, then it should be left empty. "".

Examples

visa = VISA.Visa()
visa.create_session("@py")
ports = visa.get_ports().data
port = last(ports)
visa.create_instrument(port)
numbytes = visa.write(port, "*RST;:SYSTEM:LOCK OFF", "").data
visa.writebinblock(port, message)

Writes binary data to the device.

Arguments

  • port::String: the port of the device connected via the VISA specification. You can get it using the function visa.get_ports().

  • message::Vector{UInt8}: binary data for writing. For example: [0x01, 0x00].

Examples

visa = VISA.Visa()
visa.create_session("@py")
ports = visa.get_ports().data
port = last(ports)
numbytes = visa.writebinblock(port, [0x01, 0x00]).data
visa.writeread(port, message, delay)

Writes the answer to the device and reads it.

Arguments

  • port::String: the port of the device connected via the VISA specification. You can get it using the function visa.get_ports().

  • message::String: message with the SCPI command. For example: ":CHAN1:BASE:WAV?" returns the type of signal in the first channel.

  • delay::Float64: delay for receiving a response from the device (optimal value 1.0, for older devices up to 1.5). For more information about the response delay, see the documentation of the device you are using.

Examples

visa = VISA.Visa()
visa.create_session("@py")
ports = visa.get_ports().data
port = last(ports)
writeread_result = visa.writeread(port, ":CHAN1:BASE:WAV?", 1.2).data