Touch In CHOP

From TouchDesigner 099 Wiki


The Touch In CHOP can be used to create a high speed connection between two TouchDesigner processes via CHOPs.

Data is sent over TCP/IP. The Touch In CHOP (client) receives its data from a Touch Out CHOP (server). The Touch In CHOP is similar to a Pipe In CHOP but highly optimized for TouchDesigner-to-TouchDesigner communication. For interfacing with other software or devices, see the Pipe In CHOP or the TCP/IP DAT.

To receive network data from another "server" computer (e.g. from a Touch Out CHOP running remotely), a connection must be established between the server and the Touch In CHOP before data is sent.

The data is received as time slices, and can be used to eliminate frame dropping if the sender or receiver is not running at its target frame rate. See Time Slicing and the Time Slice CHOP.

To analyze the timing of the messages coming in, attach an Info CHOP to the Touch In CHOP. It will show the internal queue size and whether it is dropping or missing data (queue_advanced_total and queue_retarded_total should not be increasing, and queue_length should not be zero).

NOTE for Windows OS - If experiencing connection issues, confirm Windows Firewall is disabled for TouchDesigner.

See also: OSC In CHOP

PythonIcon.png touchinCHOP_Class

Parameters - Touch In Page

Protocol /protocol - Selects which network protocol to use to transfer data. Different protocol's have methods of connecting and using the address parameter. For more information refer to the Network Protocols article.

Address /address - The computer name or IP address of the server computer. You can use an IP address (e.g. or the computer's network name can be used directly. If you put "localhost", it means the other end of the pipe is on the same computer.

Network Port /port - The network port of the server.

Active /active - While on, the CHOP receives information from the pipe or server. While off, no updating occurs. Data sent by a server is lost, but a pipe will store the data until Active is turned on again. If in Network mode, turning this parameter on initiates a connection, and turning it off breaks the connection.

Queue Target /queuetarget - the target queue length the CHOP will attempt to maintain.

Queue Variance /queuevariance - the range around the Queue Target that's acceptable. If the queue's length is within the target and variance range, the CHOP will not bother to adjust the queue length.

Maximum Queue /maxqueue- the maximum size of the queue when full. Incoming samples will be dropped if the maximum queue is reached.

Queue Adjust Time /adjusttime - specifies how often to repeat/drop a samples in order to get closer to the queue target range. If the value = 1 and the units = seconds, then it will try to repeat/drop a sample once per second to maintain the queue target set in the Minimum Target and Maximum Target parameters above.

Recover Outside Range /recover - If the queue size goes outside of the target size range for more than the 'adjust time', then if this option is on it will stop delivering new data or throw away a lot of data, until queue size is back in the middle of the min/max target. If this option is of the queue size will be slowly inched towards the target size instead (by dropping or repeating single frames every once in a while).

Use Synced Ports /syncports - this parameter lets you send the the data in a single global pipe if required. This can be important if various data streams must be sent in frame sync.

  • Off - uses separate ports for each port number assigned.
  • On (TCP/IP) - uses a single global pipe for all Touch Out CHOPs using this Transfer Port Type. The global pipe uses port 10500 internally to send all the global port type data together at once. The Network Port parameter is still used to determine which Touch In CHOP gets the data on the receiving side.

Standard Options and Local Variables