SUPPORT-FRONT 1952134 - Caterpillar

SNM 940 Cellular Radio
Illustration 4 g06195088
SNM 940 Cellular Radio (Front View)
(4) GPS antenna connector
(5) Power and GPS activity indicator
(6) Cellular antenna connector
(7) Electrical harness connector
(8) WLAN antenna connector
(9) WLAN indicator
Illustration 5 g06195091
SNM 940 Cellular Radio (Rear View)
(10) SIM card access doorThe SNM940 Radio has two LED indicators lights on the front face of it as shown in Illustration 4.The Green LED Indicator light (5) will provide the power supply and the GNSS statusThe amber indicator light (9) provides the wireless communications status.The two LED indicator light on the SNM940 Radio provides information of the device status for troubleshooting.The two LED lights flashing status meaning is explained in the below Table 5.
Table 5
Green LED Amber LED SNM940 Status
ON Solid OFF Powered and Initialized
Blink N/A GNSS Providing a position
Fast Blink N/A No GNSS Signal or poor Position quality
N/A ON Solid Cellular data connection
N/A Blink WLAN (Wireless local Area Network) data connection
N/A Slow Blink WLAN cellular connection
N/A Fast Blink Poor or no wireless
OFF OFF Low Power standby Blink rating
Slow Blink- 3 second on and 3 Seconds off.
Blink 1 Second on / 1 second off.
Fast blink- 200 milliseconds on / 200 milliseconds off.
Table 6
3D System Components CAN communication pinout
Component CAN Hi/Pin CAN Lo/Pin
Data Radio 4 9
GNSS Receivers P L
Body Tilt Sensor C D
3D System ECM -R2 EC520
CAN 1 5 6
CAN 2 7 8
CAN 3 9 10 The CAN components CAN troubleshooting section on the diagnostics.Note: When troubleshooting the 3D system Components, refer to the machine system schematics or 3D system components connectors pinout tables. The CAN Data Link or the Electrical Power Supply - Tests can be performed by implementing their troubleshooting steps to troubleshoot the 3D system components, CAN bus, or the power supply circuit.GNSS Problems
There are a large variety of issues that can affect GNSS satellites and the position accuracy of the GRADE system. Many of these issues are due to factors inherent in the technology. These factors should be understood and accounted for when operating the GRADE system. Some of the common issues are:
Poor satellite configuration
Loss of satellite signalPoor Satellite Configuration
This value is measured as Position Dilution Of Precision (PDOP). The GRADE display will allow the operator to monitor the PDOP. PDOP should be as low as possible, and will change throughout the day as satellites go through orbits.PDOP will also be affected if there are obstructions that prevent view of the sky such as trees, buildings, and other terrain. PDOP will tend to introduce an offset from desired grade, but PDOP issues can also introduce grade roughness as satellites appear and disappear.Loss of Satellite Signal
Loss of satellite signals eventually results in an error message on the GRADE display. The message indicates that the system no longer has a high precision location established. GRADE requires a Real-Time Kinematic (RTK) Fixed type of position solution. If signals are lost, RTK Float or Autonomous modes for the position solution are degenerated. This action will result in poor accuracy.Load Assist and Sequence Assist do not require positions to be calculated from the GNSS receiver.