Simrad HS80/MX575C, Руководство пользователя

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Installation | HS80/MX575C User Manual
Ports
The HS80/MX575C offers either NMEA 0183 serial port or NMEA 2000 port functionality.
Serial ports
The HS80/MX575C has three ports (Port A, Port B, and Port C), where:
•
Port A can be both full-duplex RS-232 and half-duplex RS-422 (transmit only)
•
Port B is full-duplex RS-422
•
Port C is for NMEA 2000 and only available via serial-to-NMEA 2000 adapter
You can receive external differential corrections via either Port A (full-duplex RS-232) or Port
B (full-duplex RS-422). You can connect up to three devices at one time using two ports. One
device can receive data via Port A (RS-422 transmit only) while two devices can transmit and
receive data via Ports A and B (one connected to Port A RS-
232 and one connected to Port B).
¼
Notes:
1.
Port A (RS-422) or Port B is required for communicating to an IMO-approved device.
2.
You can update firmware via Port A (RS-232) or Port B.
¼
Note:
The MX575C has maximum baud rate of 38400. Higher baud rates may impair beacon
signal tracking.
Serial port configuration
You may configure Port A or Port B of the GPS receiver to output any combination of data.
Port A can have a different configuration from Port B in terms of data message output, data
rates, and the baud rate of the port. This allows you to configure the ports independently
based upon your needs.
For example, if you want one generalized port and one heading-only port, you can configure
the ports as follows:
•
Port A to have GPGGA, GPVTG, GPGSV, GPZDA, and GPHDT all output at 1 Hz over a 9600
baud rate.
•
Port B for GPHDT and GPROT message output at their maximum rate of 20
Hz over a 19200 baud rate.
The messages you configure each port to output and the rate of the port will be the same
for both RS-232 and RS-422 interface levels. For example, the RS-232 Port A and RS-422 Port A
output the same data messages at the same baud rate. If the baud rate or messages for the
RS-422 port need to be changed, this needs to be commanded through the RS-232 port.
Both RS-232 and RS-422 output signals may be used simultaneously.
¼ Note:
For successful communications use the 8-N-1 protocol and set the baud rate of the
HS80/MX575C’s serial ports to match that of the devices to which they are connected. Flow
control is not supported.
Selecting Baud rates and message types
When selecting your baud rate and message types use the following formula to calculate
the bits/sec for each message and then sum the results to determine the baud rate for your
required data throughput.
Message output rate * Message length (bytes) * bits in byte = Bits/second
(1 character = 1 byte, 8 bits = 1 byte, use 10 bits/byte to account for overhead)
See “Common commands and messages” on page 27 for an example of this calculation.