Trimble - AgGPS 132

What is The Choice™ AgGPS® 132?
The AgGPS® 132 is a submeter differential accuracy 12-channel GPS receiver with The Choice™ technology. It has a combined antenna with a single antenna feedline. It is designed to be used worldwide in precision agricultural applications. The AgGPS 132 has a display and keypad to set receiver parameters.
Return to FAQ

What is The Choice technology?
The Choice technology is the combination of a GPS receiver with both a beacon and satellite differential correction receiver in the same housing.
Return to FAQ

What are the new features of the AgGPS 132?
The AgGPS 132, with The Choice technology has a display and keypad to allow both monitoring of receiver status parameters and setting up of receiver operating conditions. With The Choice technology the receiver has the capability of receiving both medium frequency beacon differential correction and L-band satellite differential correction signals with a single combined antenna.
Return to FAQ

How does Satellite differential compare with Coast Guard Beacons?
Satellite and beacon differential service differ in the following factors: Range and area of coverage, annual subscription cost, initial equipment cost and accuracy.
\ To enable a satellite differential correction receiver, all that is required is a telephone call to the appropriate supplier. Depending on which supplier is involved, the supplier will either activate the receiver with an on-the-air signal or instruct the user to activate the receiver with an encrypted activation message which the user will enter manually from the front panel of our receiver or with a computer program.
Return to FAQ

What's on the display of the AgGPS 132?

The 2-line 16-character LCD display of the AgGPS 132 shows all the status information of the GPS receiver, including: position, altitude, speed, heading, PDOP, HDOP, VDOP, satellites used, position mode, differential status, satellites' signal strength; all status information of the beacon receiver, including signal strength, signal-to-noise ratio, beacon used, beacon status, bit error rate; all status information for the L-band satellite receiver, including: signal provider, signal frequency, signal strength, signal-to-noise ratio. In combination with the keyboard, the display is used to configure all receiver settings and the I/O selections, including the NMEA messages.
Return to FAQ

How do I select different sources for differential correction on the AgGPS 132?
Using the keypad, press the down arrow to select the DGPS differential correction signal setup menu item. Then press the right arrow to set up the Satellite Signal frequency. Press the enter key to accept the change.
Return to FAQ

Can the AgGPS 132 automatically switch the source of differential signal in the event the primary signal is lost?
The AgGPS 132 can be configured to use a specific satellite signal or a specific beacon signal as the primary differential correction source. In the event of loss of the primary signal the receiver can be configured to switch automatically, after a user specified time-out, to the other differential source without any further user intervention.
Return to FAQ

How do I use TSIP Talker with the AgGPS 132?
TSIP Talker is used with the AgGPS 132 the same way it is used with the AgGPS 124, however there are only a few special functions that are available for the TSIP Talker program that cannot be programmed through the display. The most important of which is the FFT display. This display is extremely important for searching out noise sources which can interfere with the reception of the beacon signal.
Return to FAQ

What is the port configuration of the AgGPS 132?
The I/O ports may be configured for TSIP, NMEA and DGPS. The port configuration of the AgGPS 132 is the same as for the AgGPS 124. The same cables that are used for the AgGPS 124 are used for the AgGPS 132.
Return to FAQ

I live in an area without beacon coverage. What are my options if beacons are installed as part of the planned expansion?
If you do not currently have beacon coverage, then you use the AgGPS 132 and subscribe to a satellite differential service. When a beacon is activated in your area it can be received by selecting the beacon as source with the keypad.
Return to FAQ

How can I change NMEA messages on the AgGPS 132?
Using the keypad, press the down arrow until you reach the NMEA setup screen. Then press the right arrow to highlight the NMEA string you wish to activate. Press the up and down arrow to activate or deactivate the message. An asterisk (*) marks an activated message.
Return to FAQ

If I do not activate satellite differential when I initially purchase the AgGPS 132, will I still have the option of activating satellite differential in the future?
When you desire to activate the AgGPS 132 to receive satellite differential corrections, call the appropriate vendor with your user ID code. They will instruct you to turn your receiver on to receive the activation signal.
Return to FAQ

What options are available for the AgGPS 132?

The 10 Hz position update options are used when the AgGPS 132 is used in guidance applications where a higher update rate is needed for best results.

The Scorpio option is used in the United Kingdom to activate the receiver to receive the encrypted differential correction signals provided by Scorpio Marine, Ltd.

The Differential Base Station - RTCM out option allows the receiver to be used as a source of DGPS corrections. The user must enter the coordinates of the antenna and select the RTCM correction data parameters.

The EVEREST™ multipath reduction option is most noticeable in stationary applications where the multipath noise is greatest and is very important in mapping applications or when used as a differential base station. When a GPS receiver is stationary, multipath noise is an important consideration and a receiver with EVEREST multipath reduction technology provides significantly better results than one without. Everest

The AgField packs contain the hip pack, cables, batteries, charger and antenna poles to permit the user supplied AgGPS 132 receiver to be conveniently carried in portable applications and attached to user supplied laptops, pen computers or Win CE compatible handheld computers.

Return to FAQ

How does the AgGPS 132 communicate with precision agriculture instruments?
The Trimble AgGPS 132 receiver outputs NMEA data so it may be easily integrated with a variety of precision agriculture applications; such as: harvest yield monitors.
Return to FAQ

What is NMEA?
NMEA stands for National Marine Electronics Association. The NMEA 0183 Interface Standard defines electrical signal requirements, data transmission protocol and timing, and specific sentence formats for a 4800 serial data bus. The latest version is version 2.02, and can be obtained from the National Marine Electronics Association at 410-263-1742.
Return to FAQ

Who uses NMEA?

Normally, only marine GPS receivers are fully compliant with the NMEA 0183 Standard, and these receivers provide plug-and-play compatibility with other marine instruments. The NMEA 0183 standard calls for an electrical bus compatible with EIA-422. However, many resource grade GPS receivers use an EIA-232 serial data port, in order to be compatible with personal computer serial ports. While NMEA 0183 calls for a 4800 baud rate, many GPS receivers are capable of a wide range of baud rates, both faster and slower, making them more likely to be interfaced with other, non-marine instruments.

GPS receivers that mention NMEA compatibility on their data sheets usually refer to the ability to output NMEA sentences. Some of the NMEA sentences most used by GPS receivers for agricultural applications are GLL, GGA, GSV, VTG, RMC, and ZDA. These sentences contain latitude, longitude, speed, heading, time and other related information.

Return to FAQ

Why is NMEA important for agricultural users?
NMEA is important for agricultural users because it represents a standard interface that may be used in a plug-and-play manner by other precision agricultural equipment that needs GPS positions, for example, yield monitors, spray controllers, and planters. With this NMEA standard interface, software manufacturers do not have to rewrite their applications to accommodate different vendors proprietary format every time a piece of equipment is changed.
Return to FAQ

How does the AgGPS 132 connect to yield monitors?
The AgGPS receivers have a NMEA output port that is connected to the yield monitor GPS input port with an appropriate data cable.
Return to FAQ

How does the AgGPS 132 communicate with yield monitors?
The AgGPS 132 communicates with yield monitors using NMEA messages.
Return to FAQ

What NMEA messages are sent by the AgGPS 132
As shipped from the factory, the AgGPS 132 has it's NMEA output port parameters set to output the GGA, VTG, GSA, and RMC messages at a one-per-second rate, at 4800 baud with 8-N-1 protocol, which are the most common NMEA messages required by yield monitors. Other NMEA messages that the AgGPS 132 may be configured to output are GLL, ALM, ZDA, MSS, and GSV. In addition, the AgGPS 132 may be configured to output data from 1200 baud to 19.2 kilobaud.
Return to FAQ

Which yield monitors connect with the AgGPS 132?
The AgGPS receivers connect to the yield monitors manufactured by Ag Leader, Harvest Master, CASE, John Deere, RDS and Micro-Trak.
Return to FAQ