Revised: 2016-08-19
To the home page

USB-Picobus Standard Interface

The AVS-47B has a synchronous, slow, serial, low-noise primary interface called "Picobus". It has been implemented without fast programmable digital circuits in order to keep high-frequency emissions at minimum. It uses four signal lines, two out from the computer and two out from the instrument. Communication uses our proprietary "Picobus" protocol. It means roughly, that instead of any command, the complete (new) state of the instrument is transmitted from the computer as a 48-bit long binary string. The complete (old) state of the instrument is received to the computer simultaneously using the same synchronizing clock.
    The four required signals are typically obtained from hardware handshake inputs and outputs of a COM: port of a PC-computer. Most operating systems and programming languages continue supporting RS232 communication, but most computers no longer offer a physical RS232 port. Luckily, a USB-232 adapter can create a virtual serial port, which the application program can access via its USB port.
     Because of its primitive low-level nature, Picobus is not intended to be used as such. Instead, we offer one no-cost solution for LabView™ users (USB-Picobus) plus two optional protocol converters for the others (AVS47-Serial/USB and AVS47-IB).

USB-Picobus is a package of LabView Virtual Instruments (VIs). It requires a PC-type computer running Windows and at least the base version of LabView2012 or newer. Connection is usually made to an USB port via a USB-232 converter (e.g. National Instruments part 778472-01), but if the computer has a physical COM: port, such an adapter is not needed. The VIs support also the discontinued TS-530A Temperature Controller.
     The extensive package of VIs contains several application examples, like a free-running scanner with temperature display (see the picture). There are also building blocks that you can use for creating your own LabView application.
    The wire cable between the AVS-47B and the computer can be replaced by an optic fibre link USB-Picolink (option).

USB-Picobus User Guide
USB-Picobus LabView programs ZIP file
More about Picobus Short description about the protocol
Testing the Com: port How to check compatibility
AVS47-Picolink Optical Fibre Link Option
AVS-47B Configurations Alternative ways for interfacing

Veromiehentie 14