Uwis-inds100 Inductive Module User Manual

US INDUCTIVE MODULE US-INDS100 OPERATION DESCRIPTION
AND USER MANUAL 

A wireless inductive data link for digital data transmission above and underwater
REVISION 1.0 – April 2018 T.Toivola
REVISION 2.0 – April 2020 T.Toivola (RF power, gain, and duty cycle added)
REVISION 3.0 – June 2020 T.Toivola (Chapter 9, No RX only mode)
REVISION 4.0 – July 2020 P.Arvonen (Chapter 10)

The object of the Document

This document contains a description of the functional operation of the UWIS Inductive module and the user manual.

Features

Nominal features for UWIS UWIS-INDS100 inductive link are as follows:

1. The device implements the current UWC protocol specification
2. The communication range is 1.5 meters minimum
3. The frame error rate is less than 1% at a 1.0-meter range
4. There is no interference to another UWC device
5. The device accepts typical outside interference while maintaining communication range and frame error rate specifications

 Operating frequencies

Divisors using an 8 MHz peripheral clock (PERCLK) are shown in
Table 1 with operating frequencies.
Table 1 Operating frequencies.

Modulation

The UWC inductive link uses binary phase-shift keying (BPSK) modulation. The BPSK modulation works by shifting the phase of the transmit carrier by 180 degrees for every transmitted bit that is zero. When the transmit bit is one, the carrier is transmitted without change. The bandwidth used is roughly equal to the bit rate.

Host interface

The inductive module is connected to the host with a 7-pin interface cable.
Table 2 Host interface

MCU

MCU EMF32G210 converts serial data to inductive TX-signal and receives inductive RX-signal converting it to serial data. MCU runs with a 16MHz clock generating needed frequencies according to embedded firmware.

TX amplifier

MCU gives digital timing and modulation for the external mux. Mux gives modulated digital output for transmitter output amplifier. The Digital signal is then filtered to an analog signal with the needed bandwidth. Analog signal is possible to mute with host mute signal to avoid known collisions. Analog amplifier feeds output coil.
The output coil is tuned to 123 kHz to achieve the needed range.

RX amplifier

The receiver coil is tuned to max receiver sensitivity. A low noise amplifier amplifies the received signal for MCU ADC conversion. MCU receives differential signals for BPSK detection. There is no RX-only function mode on this device, TX is always functional and so the receive-only mode cannot be measured.

Module usage position

The inductive module is located inside the host enclosure to achieve mechanical, moisture or ESD protection. Host devise nominal location and direction give an optimal range for the inductive antenna.

FCC Statement

This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions:
(1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation. Changes or modifications not expressly approved by the party responsible for compliance could void the user’s authority to operate the equipment.

UWIS Oy, Kaarinantie 700
20540 Turku, Finland
[email protected]
+358 40 514 0565
www.uwis.fi

References

• A new system for diver navigation and dive planning – UWIS