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There is a limit to the amount of data that can be sent across the serial port. The amount of data that can be sent depends
on how fast the communication rate between the two devices is (Baud Rate), the number of NMEA Messages sent, the
Rate the messages are sent (times per second), and the amount of information that is in the message that is sent. The
GeoSteer system verifies that it can physically send the amount of data at the specified Baud Rate the operator sets. If the
operator attempts to send too much data at the specified Baud Rate, they will be given a warning message when they
press the Back Menu Arrow.
Before the operator is allowed to exit this screen, they must
reduce the number of NMEA Messages sent, the Rate the
messages are sent, or, if allowed by the 3rd party device, increase
the Baud Rate. Always use the least number of messages
required to ensure acceptable performance.
Edit
To Edit the Rate of any of the NMEA Messages, follow the
procedure below:
1.
From the GPS tab, press the NMEA Out button.
2.
Press the Blue Up/Down Arrows or directly select Port A
Messages from the list on the right.
3.
Use the Gray Up/Down Arrows or directly select one of the
NMEA Messages that is to be modified.
4.
Press the Edit button.
Use the Gray Up/Down Arrows or directly select the desired
transmit rate.
Press the Green Check Mark to save the settings or press the Red
X to cancel.
The GGA Messages has an additional setting that can be
configured. One of the values of the GGA message is the GPS
Quality value. The GPS Quality tells 3rd party devices the
correction source (SPS, DGPS, or RTK) that was used to calculate
the NMEA position. Some 3rd party devices require that this
value be set to DGPS (2) in order to function properly.
Other 3rd party devices require a RTK Fixed (4) position to be
used. The GeoSteer system can be configured to send out two
versions of the GGA Message in order to make it compatible in
either case. They are:
Current
—The GGA Message sends the GPS Quality value based
on the actual correction source that calculated it. 3rd Party
devices will receive a value of 1, 2, 4, or 5 depending on what the true correction source is. This is the industry standard and
default condition.