The visca backend

The visca backend provides control of compatible PTZ (Pan, Tilt, Zoom) controllable cameras via the network. The VISCA protocol has, with some variations, been implemented by multiple manufacturers in their camera equipment. There may be some specific limits on the command set depending on the make and model of your equipment.

This backend can connect to both UDP and TCP based camera control interfaces. On Linux, it can also control devices attached to a serial/RS485 adapter.

Global configuration

The visca backend does not take any global configuration.

Instance configuration

Option Example value Default value Description
id 5 1 VISCA Camera address (normally 1 for network communication
connect 5678 none Camera network address and port. Default connection is TCP, when optionally suffixed with the udp keyword, connection will be UDP
device /dev/ttyUSB0 115200 none (Linux only) Device node for a serial port adapter connecting to the camera, optionally followed by the baudrate
deadzone 0.1 0.1 Amount of event value variation to be ignored for relative movement commands

Channel specification

Each instance exposes the following channels

  • pan: Pan axis (absolute)

  • tilt: Tilt axis (absolute)

  • panspeed: Pan speed

  • tiltspeed: Tilt speed

  • zoom: Zoom position

  • focus: Focus position

  • autofocus: Switch between autofocus (events > 0.9) and manual focus drive mode

  • Switch between automatic white balance mode (events > 0.9) and manual white balance mode

  •, Red/Blue channel white balance gain values

  • home: Return to home position

  • memory<n>: Call memory (if incoming event value is greater than 0.9)

  • store<n>: Store current pan/tilt/zoom setup to memory (if incoming event value is greater than 0.9)

  • move.left, move.right, move.up, move.down: Move relative to the current position. Set speed is multiplied by the event value.

  • move.x, move.y: Move relative to the current position along the specified axis. Set speed is multiplied by the event value scaled to the full range (ie. 0.0 to 0.5 moves in one direction, 0.5 to 1.0 in the other).

Example mappings:

control.pan > visca.pan
control.tilt > visca.tilt
control.btn1 > visca.memory1
control.stick_x > visca.move.x
control.stick_y > visca.move.y

Compatibility list

Manufacturer Exact model(s) tested Compatible models Result / Notes
ValueHD VHD-V61 Probably all ValueHD Visca-capable devices Everything works except for absolute focus control
PTZOptics Probably all of their PTZ cameras See ValueHD

Known bugs / problems

Value readback / Inquiry is not yet implemented. This backend currently only does output.

Some manufacturers use VISCA, but require special framing for command flow control. This may be implemented in the future if there is sufficient interest. Some commands may not work with some manufacturer’s cameras due to different value ranges or command ordering.

Please file a ticket if you can confirm this backend working/nonworking with a new make or model of camera so we can add it to the compatibility list!