MiniPlex 3USB- 4 Ch NMEA Multiplexer/USB

Part #1131

MFG #MPX3-USB

Features

The MiniPlex-3 Series has a rich set of features and configuration options, enabling the user to tackle almost any NMEA bottleneck or interface problem. The supplied Windows utility MPX-Config3 allows full configuration of the multiplexer and monitoring of NMEA data passing through the multiplexer.

NMEA routing

NMEA data can be routed from any input to any output. A default route can be set as well as specific routing rules for individual NMEA sentences.

Computer data can be routed to any NMEA output, to be merged with other NMEA data or to override this data. This enables automatic switching between computer based navigation and GPS/instrument based navigation.

NMEA filtering

A flexible NMEA filter can be configured to pass or block specific sentences from each input channel. This greatly reduces the chance of an overflow and the resulting loss of data. Many GPS receivers for instance, transmit an abundance of sentences every second, accounting for 85% of the available bandwidth of an NMEA 0183 port at 4800 Baud. By blocking unwanted or unnecessary sentences, bandwidth is preserved for other instruments. The filter can also be configured to reduce the rate of specific NMEA sentences.

Flexible communication speed

The communication speed of all inputs and outputs can be set from 4800 to 57600 Baud to allow connection of devices that operate at non-standard (4800 Baud) communication speeds like integrated weather sensors, gyrocompasses or AIS receivers and transponders.

SeaTalk^® conversion

When Input 1 is set to SeaTalk® mode, this NMEA input becomes a bi-directional SeaTalk® port, offering conversion between the most common SeaTalk datagrams on a Raymarine SeaTalk1^® network and their NMEA 0183 counterparts. These sentences are combined with NMEA sentences received on the other inputs. When Priority is enabled, SeaTalk data can be assigned highest or lowest priority. Currently, only conversion from SeaTalk1 to NMEA 0183 supported. Conversion from NMEA 0183 to SeaTalk1 will be available soon through a firmware update.

Real-Time forwarding

Gyro- and fluxgate compasses produce NMEA sentences at a high rate (10 sentences/second or more). This can lead to a buffer overflow in the multiplexer. Although this overflow is handled properly without data corruption, it will lead to a delay of NMEA sentences of up to 20 seconds in extreme situations. This produces a severe problem for autopilots, which cannot make proper course corrections when their heading feedback is delayed for 20 seconds. The Real-Time option prevents this delay by bypassing the buffer of that specific channel and forwarding the data immediately to the multiplexer's NMEA output. As a result, the heading is never delayed more than 0.2 to 0.5 seconds, depending on the amount of other NMEA sentences passing through the multiplexer.

Priority

With Priority enabled, similar NMEA sentences on different inputs are only passed from the input with the highest priority. When for instance two GPS receivers are connected to inputs 1 and 2, and both transmit the same type of NMEA sentences, only those received on input 1 are passed. An adjustable time-out ensures that similar sentences from the GPS at input 2 are passed when the GPS at input 1 stops sending these sentences. Optionally, GPS sentences are checked for a valid status field, causing automatic switchover when the primary GPS loses satellite signal.

An additional option to check the GPS status flags can be enabled to ensure that data received from a GPS which lost satellite reception is also blocked.

Channel information

This features adds an extra $--STN sentence or a TAG block to NMEA sentences to indicate on which NMEA input a sentence is received.

Talker ID substitution

Talker ID substitution changes the talker ID of incoming sentences. The talker ID can be specified for each input channel. This option is useful for software or instruments that expect a specific talker ID or to distinguish between sentences from two similar instruments.

NMEA conversions

The MiniPlex-3 offers several conversion options for NMEA sentences:

· Magnetic to True heading conversion and vice versa

· GPS speed to Log speed and vice versa

· Reverse True heading

· Old (VWR) to new (MWV) wind sentences and vice versa

· Relative/Apparent to Theoretical/True wind

· RMC to GGA

Specifications

Documents

Prop 65