The purpose of these "Technical Sheets" is to inform the reader on the exact functionality that is obtained when using specific SoftTALK products with HarTALK. This frame also provides an indicator of future developments that are currently under way in COCOON.
In order to understand the functions that HarTALK and SoftTALK provide when used in tandem, the reader must first understand the HarTALK protocols.
Three Camera Communication Protocols are used to facilitate communications between HarTALK and the camera. These are:
1. Settings and Download Protocol (SDP)
SDP is a high-level protocol that allows software to specify settings on the camera or to request the download of Data from the camera.
Function: This protocol facilitates the following:
- To make setting changes on the camera
- To download data from the camera (such as the data on up to 99 films taken on the camera, such as shutter speed, f-stop, film speed, frame number, etc.)
Application: SDP facilitates the ability to:
- Enable HarTALK to communicate with SoftTALK as well as with other programmes on the market similar to SoftTALK (although SoftTALK is highly recommended).
- Enable data requests and setting changes over slow serial speeds.
2. High Speed Serial Protocol (HSSP)
HSSP is a unique high-speed, low-level serial protocol that allows HarTALK to speak to the camera at speeds that are unequalled by any other serial camera interface on the market.
Function: This protocol (that is unique to HarTALK) allows the camera to be directly controlled by external controllers which may be either analogue electronic circuits or digital devices and electronic controllers, such as:
- Electronic remote control units, such as RC1 (external circuit)
- Computers - including hand-held computers (digital devices)
- Digital remote control devices
Application: HSSP facilitates the ability to:
- Focus / Shoot the camera over a serial link with a negligible time delay (latency) from the moment that the command has been issued by the external controller to the camera's physical response. If the camera is on standby, then this delay can be as little as 75 milliseconds. Normally this latency on non-HarTALK serial devices can be various seconds. A complete series of camera response times with HarTALK is published in our downloadable Electrical Specification of HarTALK (click here to download elecspec).
- Facilitate computerised control of the camera by an external digital controller (such as a PC) to take sequences of photographs with complex pre-defined instruction sets (for more information, see APT functionality below).
- Change Settings via fast remote control (as may be required by APT or future applications).
For all HarTALK and SoftTALK communications only the Settings and Download Protocol and the High Speed Serial Protocol would be required. The third protocol was developed for scientific use only.
3. Direct Remote Control Protocol (DRCP)
DRCP is another low-level protocol unique to HarTALK
that allows the camera to be directly controlled by an external
digital controller, such as a computer or a hand-held remote
controller, via a parallel connection.
Function: This protocol provides the same functionality
Application: DRCP has been specifically developed
to provide scientific users and hobby electronics enthusiasts
with the ability to develop custom (home made) applications that
would be significantly easier to integrate with HarTALK using
this particular protocol than with the High Speed Serial Protocol.
Requirement: The use of this protocol would requires
the additional use of a computer's parallel port to communicate
with HarTALK (download elecspec for details).
Further info on protocols are being compiled