Satellites

Current number of satellites tracked by the GPS receiver display in this status line. If using dual-GPS, status line displays the number of satellites as #/# Satellites in view. The first number applies to the external GPS receiver, the second number applies to the internal GPS receiver.

Three (3) satellites are required for coordinate calculations. Four (4) satellites are required for calculating a 3D position (latitude, longitude, and elevation). The more satellites tracked, the higher accuracy of the GPS receiver.

GPS status

Status line may include any of the following messages:

• Receiving GPS

• Initializing

• Waiting

Information about the serial connection displays in parentheses during the startup process, such as Initializing (V 236). It shows a GPS status byte (V or FF) and the number of received characters. GPS status bytes (V and FF) indicate whether or not the receiver is receiving GPS packets. V indicates valid GPS packets received and FF indicates no GPS packets received.

If received characters is zero (0) or does not increase, verify the GPS receiver is securely connected to the Allegro QX and communication settings are correct (COM port and baud rate).

GPS coordinates

Shows longitude, latitude, and elevation coordinates received from a minimum of 3 satellites.

Coordinates update every second. With a clear view of the sky, GPS accuracy without differential correction is about 10 meters (32.8 feet). Sub-meter accuracy is reported after applying differential correction when using a second GPS receiver (dual GPS), such as the Trimble GPS Pathfinder Pro XR.

DOP values

DOP (dilution of precision) values identify the accuracy of GPS readings. When a DOP value is zero (0), the GPS receiver does not report the value. When the value is between 1 and 3, GPS accuracy is good.

PDOP refers to position dilution of precision; VDOP refers to vertical dilution of precision; HDOP refers to horizontal dilution of precision; and TDOP refers to time dilution of precision.

Age of fix

Shows the time since the last GPS satellite fix. Age of fix appears only when the GPS satellite signal is lost. It appears ten seconds after losing the satellite signal. Information displays in the following manner:

• When age is less than 10 seconds, field is empty.

• When age is less than 1 minute, number of seconds display as nn sec, such as 35 sec.

• When age is less than 60 minutes, number of minutes and seconds display as mm:ss, such as 12:14.

• When age is undetermined, an asterisk (*) displays.

GPS time

GPS time displays when a GPS time signal is received and the Offset option is disabled.

Updates display every second when GPS time is available. GPS time displays in 24-hour format and may include the suffix letters P and/or Z. P indicates a PPS (one pulse-per-second) time signal is being received. Z indicates a GPS time packet is being received.

When GPS time is unavailable or the GPS time signal is more than 10 minutes old, this area of the GPS Status window is empty. When Offset is enabled, offset values (such as 2, 1, 5) or asterisks (*, *, *) display instead of GPS time.

Offset

Offset shows the distance between two points. To use Offset, tap Offset and then move to a different location. Offset values display inside parentheses and are calculated as feet or miles. For example, with an offset of (1, 2, 3):

• 1 is the east-west offset (W positive)

• 2 is the north-south offset (N positive)

• 3 is the vertical offset

An offset distance higher than 0.1 degree (about six miles) displays as asterisks inside parentheses (*,*,*). When Offset is enabled, GPS time does not display.

Beep

If you want the Allegro QX to beep each time GPS readings update, tap Beep to enable the option.

u-blox WGS84

Status line showing the current datum setting for a u-blox compatible GPS receiver. This status line does not display for all other GPS receivers, such as a Trimble GPS receiver.