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TCP Read (TCP Read Text) (G Dataflow)

Last Modified: December 18, 2017

Reads a number of bytes from a TCP network connection and returns the results as string data.

Programming Patterns
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mode

The behavior of the read operation.

This input determines the following aspects of this node's behavior:

  • The condition(s) that must be met before this node returns data
  • The kind of data that this node returns
Name Description
Standard

Waits until all bytes to read arrive or until this node times out before returning data. This node returns the number of bytes read so far. If fewer bytes than the number you requested arrive, this node returns the partial number of bytes and reports a timeout error.

Buffered

Waits until all bytes to read arrive or until this node times out before this node returns data. If fewer bytes than the number you requested arrive, this node returns no bytes and reports a timeout error.

CRLF

Waits until all bytes to read arrive, until this node receives a carriage return (CR) followed by a linefeed (LF) within the number of bytes to read, or until this node times out before this node returns data. This node returns the bytes up to and including the CR and LF if it finds them in the bytes to read.

Immediate

Returns data as soon as this node receives any bytes to read. This node waits the full timeout only if it receives no bytes to read. This node returns the number of bytes received so far and reports a timeout error only if this node receives no bytes.

Default: Standard

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connection ID in

A network connection refnum that uniquely identifies the TCP connection.

Use TCP Open Connection to generate a refnum to wire to this input.

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bytes to read

The number of bytes this node reads.

Wire a value greater than 0 to this input to read data.

Default: 0

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timeout ms

Time, in milliseconds, that the node waits to complete before reporting a timeout error.

Wire a -1 to this input to wait indefinitely.

Default: 25,000 ms

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error in

Error conditions that occur before this node runs.

The node responds to this input according to standard error behavior.

Standard Error Behavior

Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.

error in does not contain an error error in contains an error
If no error occurred before the node runs, the node begins execution normally.

If no error occurs while the node runs, it returns no error. If an error does occur while the node runs, it returns that error information as error out.

If an error occurred before the node runs, the node does not execute. Instead, it returns the error in value as error out.

Default: No error

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connection ID out

Same value as connection ID in.

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data out

The data read from the TCP connection.

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error out

This node can return the following error codes.

56 The network operation exceeded the user-specified or system time limit.
62 The system caused the network connection to be aborted.
64 The network connection is not yet established.
66 The network operation was closed by the peer.
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Note  

This is not a comprehensive list of errors this node can return.

Standard Error Behavior

Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.

error in does not contain an error error in contains an error
If no error occurred before the node runs, the node begins execution normally.

If no error occurs while the node runs, it returns no error. If an error does occur while the node runs, it returns that error information as error out.

If an error occurred before the node runs, the node does not execute. Instead, it returns the error in value as error out.

Where This Node Can Run:

Desktop OS: Windows

FPGA: This product does not support FPGA devices

Web Server: Not supported in VIs that run in a web application


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