Surface Deployed Acoustic Modem 6

What you need to know

Transfers data at up to 9,000 bps
Highly reliably; built around our Wideband^®2 acoustic and 6G^® hardware platform
Options for buoys, unmanned surface vehicles and ships

Modem 6 acoustic modems are a cost-effective solution for simple point-to-point data transfer from a wide range of sensors including, data loggers, ADCPs, CTDs and other subsea instruments. It’s therefore ideal for applications such as: near real time data streaming, data harvesting or subsea command and control. Built around our field-proven 6G hardware and Wideband 2 acoustic signal platforms, operating at speeds between 200 and 9,000 bps, you can be assured of reliable communications performance, whatever your application, water depth or duration of deployment.

IS MODEM 6 RIGHT FOR ME?

Modem 6 acoustic modems are aimed at simple applications, which do not require the more complex functions of our core 6G range, such as precise positioning, on-board sensors or complex multi-node array telemetry. If you need any of these capabilities and/or an OEM solution, please get in touch so that we can identify the right solution for your project.

SURFACE DEPLOYED ACOUSTIC MODEM 6

We offer a variety of surface deployed acoustic Modem 6 to suit any operational deployment scenario and data transfer mission. You can mount them on a variety of surface platforms ranging from buoys to all sizes of vessels – both manned and unmanned – to interact with any of our underwater Modem 6 instruments.

OUR ACOUSTIC MODEM OPTIONS -point-to-point data transfer

Our family of surface deployed Modem 6 instruments benefit from same mechanics and electronics you’ll find in our other 6G dunker systems. These are trusted by leading offshore operators to perform in the most demanding marine environments and operational scenarios. With 6G at their heart, they are also compatible with our other 6G instruments, including our RT6 range of acoustic releases.

Modem 6 Transceiver
Offers ultimate performance with excellent vessel noise rejection. Multiple receive elements ensure the highest data rates possible . Can be upgraded to Ranger 2 USBL transceiver.

• MF and LMF options available
• Optimised for noisy environments
• Ideal for permanent vessel fit
• Surface system kit: SIU, cable drum, cage

Modem 6 Dunker
Available in MF and LMF, omni and directional, the Modem 6 Dunker is a rugged easy-to-mount instrument designed for excellent horizontal and shallow water communication

• Up to 9000 bps true user data rate
• Shock mounted electronics
• MF/LMF omni or directional transducers
• Rugged, easy to mount housing

Modem 6 Mini-Dunker
Bump guards offer protection from knocks during deployment and recovery

• Perfect for small vessels
• RS485 comms interface
• Surface system kit: Mini-Dunker, SIU and cable

More about this product

Surface Deployed Acoustic Modem 6 Specifications & DataSheet

Modem 6 Transceiver

Feature	Modem 6 Transceiver 8182-0001	Modem 6 Transceiver 8193-0012
Operating Frequency	MF (21–32.5 kHz)	LMF (14–19 kHz)
Operating Range	Up to 7,000 metres	Up to 12,000 metres
Acoustic Coverage	Up to ± 90º	Up to ± 90º Optimised for deep water (depending on frequency of operation)
Transmit Source Level re 1 uPa @ 1 m	200 dB	200 dB
Tone Equivalent Energy (TEE)*	206 dB (13 JA)	206 dB (13 JA)
Transceiver 6 Operating Voltage	48 V dc (±10%), typical 15 W, max 120 W – supplied by the SIU
SIU Operating Voltage	90–260 V ac, 50/60 Hz, 200 VA max – power out 48 V dc, 2.0 A max
Communications	Primary and secondary port: RS485 (half-duplex) SIU input: RS232	Primary and secondary port: RS485 (half-duplex) SIU input: RS232
Operating Temperature	-5 to 40ºC
Storage Temperature	-20 to 45ºC
Mechanical Construction	Aluminium bronze
Dimensions; Height x Diameter	370 x 225 mm	439 x 310 mm
Weight in Air /Water**	28/15 kg	41/20 kg

Surface System Kit	Sonardyne Part Number
Surface Interface Unit (SIU)	620-7079
Cable Drum (100 m)	641-3614
Deck Cable (5 m)	820-0127
Dunker Cage	641-3612

*TEE – WBv2+ signals are 4x the duration of Sonardyne tone signals (WBv1 & WBv2 are 2x). The TEE figure shows the operational performance when comparing wideband and tone systems.
Detection performance is directly related to the signal energy (Joules (Watt seconds)) and not power. WBv2+ signals are longer in duration (greater energy) than WBv1 and Tone, therefore the detection performance is the same or improved for low transmit source levels.

**Estimated Weights.

Modem 6 Dunker

Feature	Modem 6 Dunker Type 8307-1351	Modem 6 Dunker Type 8307-1353	Modem 6 Dunker Type 8307-1355	Modem 6 Dunker Type 8307-1356
Depth Rating	1,000 metres	1,000 metres	1,000 metres	1,000 metres
Operating Frequency	MF (21–32.5 kHz)	MF (21–32.5 kHz)	LMF (14–19 kHz)	LMF (14–19 kHz)
Transducer Beam Shape	Omni-directional	Directional	Omni-directional	Directional
Transmit Source Level (dB re 1 µPa @ 1 m)	187–197 dB (4 levels)	190–202 dB (4 levels)	187–197 dB (4 levels)	190–202 dB (4 levels)
Tone Equivalent Energy (TEE*)	193–202 dB	196–208 dB	193–202 dB	196–208 dB
Receive Sensitivity (dB re 1 µPa)	90–120 dB (7 levels)	80–120 dB (7 levels)	90–120 dB (7 levels)	80–120 dB (7 levels)
Serial Comunications	Primary and secondary port: RS485 (half duplex) SIU input: RS232
Dunker 6 Operating Voltage	24 or 48 V dc (±10%) – supplied by the SIU
SIU Operating Voltage	90–260 V ac, 50/60 Hz, 200 VA max – power out 48 V dc, 2.0 A max
External Power Active (listening) Peak (transmission)	<3 W typical (max 6W when charging) <80 W
Battery Life – Li-ion (Listening)	3 days
Mechanical Construction	Super-duplex stainless steel
Dimensions; Length x Diameter	692 x 200 mm	660 x 200 mm	586 x 200 mm	641 x 230 mm
Weight in Air/Water**	24/16 kg	26/17 kg	20/14 kg	28/17 kg
Connector Type	AGP (8-way female)

*TEE – WBv2+ signals are 4x the duration (WBv1 & WBv2 are twice) of Sonardyne tone signals, therefore the TEE figure is to give the user an idea of the operational performance when comparing Wideband and Tone systems.

** Estimated weights

Modem 6 Mini-Dunker

Feature		Modem 6 Mini-Dunker 8244-3151	Modem 6 Mini-Dunker 8244-3155
Depth Rating		3,000 m	3,000 m
Operating Frequency		MF (21–32.5 kHz)	LMF (14–19 kHz)
Transducer Beam Shape		Omni-directional	Omni-directional
Source Level (re 1 µPa @ 1 m)	High Power	187 dB	190 dB
	Low Power	181 dB	187 dB
Tone Equivalent Energy (TEE)* WBv2+	High Power	193 dB	196 dB
	Low Power	187 dB	193 dB
Serial Communications		Primary and secondary port: RS485 (half-duplex) SIU input: RS232
Modem Mini Dunker 6 Operating Voltage		24 or 48 V dc (± 10%) – supplied by the SIU
SIU Operating Voltage		90–260 V ac, 50/60 Hz, 200 VA max – power out 48 V dc, 2.0 A max
External Power Consumption	Sleep	<300 mW
	Wideband Listening	<500 mW
	Battery Charging	6 W
	Peak (Transmission)	<50 W
External Power Switch		Yes
Battery Life (li-ion 15 V)	Listening	30 Days
Operating Temperature		-5 to 40ºC
Storage Temperature		-20 to 55ºC
Mechanical Construction		Anodised aluminium alloy and plastics
Dimensions: Diameter x Length		98 mm x 499 mm
Weights in Air/Water**		5.1/2.2 kg

Surface System Kit
Surface Interface Unit (SIU)		620-7079
Deck Cable (20 m)		820-0834

**Estimated weights

Integration Manual for the Modem 6 Family

The Integration Manual for the Modem 6 Family (IM-Modem 6) provides the technical information required to integrate Modem 6 products (Types 8182, 8193, 8244 and 8307) to a vehicle or platform. Modem 6 shares a common acoustic and serial interface and consequently the manual is intended to enable users to set up the products to achieve several common scenarios, including:

Near Real Time Remote Data Streaming
Subsea Sensor Data Harvesting
Vehicle Data Harvesting
Vehicle Command and Control
Acoustic Command and control

Download your copy here>>

FAQs

What Product(s)?

MODEM 6 (POINT TO POINT) OR 6G TELEMETRY (NETWORK COMMS)
While Modem 6 uses the same field proven technology as our core 6G range, it is aimed at users who do not require the more complex functions of our core 6G range, such as: precise positioning, on-board sensors or complex multi-node array telemetry. As such it is ideally suited for simple applications that require a dedicated point to point data (address to address) transmission capability, while our core 6G products, including OEM solutions, are available for more challenging applications. If you’re unsure, please get in touch so that we can identify the right solution for your project.

WHAT MODEM 6 PRODUCT BEST SUITS MY APPLICATION?
All Modem 6 products utilize the same acoustic and serial protocol allowing a mix-and-match approach to suit a wide range of operating scenarios. The smaller Modems (Sub-Mini and the Mini) are suitable for vehicles and are both fitted with smaller rechargeable batteries. The standard Modem 6 is significantly larger but boasts increased transmission power and is suited to powering external equipment for long duration deployments.

HOW MANY TOPSIDE MODEMS DO I NEED?
A single topside modem can communicate individually with over 100 subsea modems, limited only by the number of unique acoustic addresses available.
Sonardyne recommends the Modem 6 Transceiver (Type 8182 & 8193) as a topside unit because it provides the most robust connection through a combination of increased SNR and superior processing gains.

Performance

WHAT IS THE TYPICAL POWER CONSUMPTION OF A MODEM 6?
All subsea Modem 6 variants have quiescent power less than 50 milliWatts. The transmission power level is configurable allowing the battery life to be optimized for the slant range. Typically, 1 megabyte of data can be transferred (at 9000 bps) using less than 1.5 Watt-hour.

HOW MUCH LATENCY IS TO BE EXPECTED?
The latency is governed by:
• The through-water travel time which is governed by the distance divided by the sound speed
• The duration of the telemetry which is governed by the amount of data being sent and the selected telemetry scheme

WHAT DATA RATES SHOULD I EXPECT?
The desired actual acoustic data rate can be selected by picking from a set of telemetry schemes. The environmental conditions (SNR) will dictate what telemetry schemes can be used effectively.
Available telemetry schemes
The lower telemetry schemes are most robust whereas the higher schemes make better use of the battery life, allowing more data to be sent with the same amount of power. Supported telemetry schemes include:
• TS0 (100 bits/s)
• TS1 (200 bits/s)
• TS2 (400 bits/s)
• TS3 (900 bits/s)
• TS4 (3000 bits/s)
• TS5 (6000 bits/s)
• TS6 (3500 bits/s)
• TS7 (9000 bits/s)

What is meant by SNR?
SNR is an abbreviation for Signal-to-Noise Ratio and is a measure which describes the ratio of signal power to the noise power. A good signal to noise ratio helps when trying to achieve a reliable acoustic communications link.

What affects SNR?
The following all affect the ratio of signal to noise power:
• The acoustic channel (deep fading caused by reverberant geometries)
• The source level of the transmitting Modem 6
• The gain level used by the receiver electronics
• Electrical noise sources, e.g. noise conducted on the power lines or induced by modulated signals to control thrusters etc.
• Cable length and inadequate shielding of cables

Features

IS SIMULTANEOUS BROADCASTING AND RECEPTION OF MESSAGES SUPPORTED?
Modem 6 can send and receive data from multiple modems as long as the modem transfers are separated in time (i.e. simultaneous broadcasting of messages is not supported).

DOES MODEM 6 SUPPORT THE MODBUS PROTOCOL?
No, there is no official support or testing for MODBUS although the Modem 6 supports binary data and will likely frame MODBUS messages correctly.

IS THERE A HANDSHAKING MECHANISM OR OTHER LINK ESTABLISHING SEQUENCE?
The Modem 6 doesn’t use any initial handshaking or establishing sequence as the power levels, gain and telemetry scheme are configured ahead of time. There is a small header (10 bytes) appended to each packet that is used internally by the Modem to transfer acknowledgement and status information.

HOW IS DATA SENT OVER THE LINK (WHAT IS MDFT)?
Modem 6 sends and receives data using MDFT (modem data frame transfer). MDFT is Sonardyne’s overall acoustic protocol for transferring data, used in Modem 6 products. Data is split into frames prior to transmission across the acoustic link, it is then reassembled at the other end before being outputted to the user.

What is the maximum MDFT frame size?
The maximum frame size (denoted here in terms of user payload) depends on the selected telemetry scheme.
• TS1 has a maximum frame size of 1,376 bytes
• TS2 has a maximum frame size of 2,656 bytes
• TS3 has a maximum frame size of 5,728 bytes
• TS4 has a maximum frame size of 27,488 bytes
• TS5 has a maximum frame size of 55,136 bytes
• TS6 has a maximum frame size of 30,048 bytes
• TS7 has a maximum frame size of 83,808 bytes

What if my payload is more than the maximum MDFT frame size?
In Fire and Forget mode the Modem 6 will continue to transfer the remaining data as long as the previous frame was successfully transferred. In Acknowledged mode the MDFT command reply will indicate that more data is available and another MDFT transfer can be scheduled to collect the remaining data.

WHAT MODES ARE AVAILABLE?
Modem 6 supports two modes.

Acknowledged Mode
The Acknowledged mode uses full two-way communications to ensure that all data sent through the acoustic link is received by the user. Any data lost due to environmental challenges will be re-requested automatically. This mode is excellent for ensuring all data is received, however it can compromise the speed of the link in challenging conditions.

Fire and forget mode
The Fire and Forget mode continuously streams any new data to minimise latency, for applications where losing the occasional piece of data is not critical. Any data that is missing will not be re-requested. This is ideal for relaying near real time sensor data.

HOW IS DATA VALIDATED?
Modem 6 uses advanced CRC (Cyclic Redundancy Checks) to ensure the integrity of any data received by the user. CRC is an error detecting code which is commonplace in digital networks; raw data files are assigned check values when transmitted which can be used at the receiving end to check for corrupt or missing data. CRC also attempts to correct corrupt data, without needing to re-request it.

What if I still have unanswered questions?

Please contact our dedicated support team by emailing: support@sonardyne.com