Universal transceiver that interfaces instrument systems
The Universal serial bus TRANSceiver (UTRANS) interfaces instrument systems to any computer with a USB port. UTRANS automatically detects the port type and configures itself for USB-1.1 or USB-2.0, as appropriate. UTRANS is an integral part of all tethered instruments and acts as the link connecting the ship-board data acquisition computer to the instrument cable (Figure 2). In this configuration the user achieves intelligent and flexible real-time data acquisition. In internally recording instruments, UTRANS links an internal single-board PC/104 data acquisition computer to the local instru-mentation. This dual-purpose flexibility of UTRANS means that tethered and autonomous (internally recording) instruments have all other internal electronics in common, allowing the user to easily convert from tethered to autonomous operation without significant additional costs.
As well as linking to the USB port on a host computer, UTRANS also links to remote instruments on a tether using a single pair of conductors for bi-directional high-speed serial communication. There can be up to 32 remote instruments connected to UTRANS, but typically there is only one remote instrument. The list of channel num
bers (or addresses) and the sampling rate chosen by the user (in a setup file) are loaded into UTRANS via the USB link (Figure 2). UTRANS transmits this list at the chosen rate continuously from its internal address FIFO and gathers the data from the remote instruments in its data FIFO. When a “record” length of data has been accumulated, they are transmitted to the host via the USB. This process is started and stopped by the host. The serial data and addresses are transmitted as 16-bit words and encoded with Manchester II to form a secure return-to-zero stream in the tether. The maximum data rates are cable length dependent but rates of 500 kilo-bits per second are possible with a 2500 m 22 gauge cable.
Download the product data sheet (PDF).
