During the last four years the system has seen considerable expansion with many new camera makes and models being added, together with pan, tilt, zoom and focus control for many types of remote head.

The basic system allows complete separation between CCU operators and remote head operators, with both being able to control up to five separate cameras and/or remote heads on a single data cable.

Technical overview

Unlike most serial data control systems, which use high-speed digital signals, the Camera Corps system uses modems to convert the digital data into audio style tone signals before transmission. This has many advantages, which include virtually no limit on distance, as well as easy transmission over simple RF links and telephone lines. By using balanced transformer coupling at both transmission and receiving points, earth loops and hum problems are virtually eliminated.

Standard audio cables or CAT5 data cable can be used for data transmission. The data is simply ‘paralleled’ using XLR3 splitters for transmission to multiple cameras/heads.

The transmission data rate can be set on all sending devices to 1200, 2400 or 4800 baud. 2400 baud is normally used, with 1200 being necessary for some RF and telephone systems, or very long cable runs.

All receiving devices will auto detect the incoming baud rate after receiving a few initial bytes of data.

The transmitting devices have level adjustment available, but in practice this is unlikely to be needed as the receiving devices can cope with a wide input level range. Occasionally, if five receiving devices are paralleled together on a long cable run it may be necessary to increase the send level slightly. The nominal send level is 1v pk to pk  (–6db). This measures as approximately 0.4v on the AC range of a multimeter. Standard audio XLR3 connectors are used with pins 2&3 used for the signal and pin 1 for earth.

There are three main components to a system that controls both camera and remote head. The first component is the CCU panel situated in the OB truck where the engineer can select up to five different cameras on a single panel. These cameras can be different makes/models if required.

Data from the CCU panel is sent to the remote head operator’s position where it is mixed in the P&T switcher box with data generated by the PTZF Switcher Box. From here the data is split and sent to the remote head/camera locations where it is decoded by Interface Boxes into analogue signals for the P&T head, and the correct data format required by particular camera makes/models.

The interface boxes have a channel selector switch that enables them to detect and decode only the data intended for that particular channel.

To assist in testing and setting up the system it is possible to generate data test signals in the form of cue/tally light commands. The P&T switcher box will generate a red cue command if the zoom reverse button is pressed, which will light the red cue on the interface box if everything is working correctly. The CCU panel can also generate a test cue that will light the cue lights on both the P&T switcher box and the interface box.