Connecting a Z-Max/Z-Extreme to Network/VRS/DirectIP without a GSM Module

Connecting a Legacy Z-Max to VRS Network

This method works with both ‘SurvCE’ and ‘FAST Survey’.

The easiest way to connect a Z-Max (or Z-Extreme) to a NTRIP or Direct IP is not with the factory GSM module. It is with a data collector, connected to the internet by Wi-Fi through a Mi-Fi device (or Bluetooth to cellphone,) and a serial connection from a COM port on the data collector to the Z-Max.

To use Wi-Fi you will need a data collector that has Wi-Fi and a hardwired serial port (Carlson Surveyor+.) You may alternatively use a BlueTooth connection to a cell phone and a hardwired connection to a serial port (Ashtech MMCX, MM100, PM100, PM200, Carlson Allegro.)

Advantages of Using Mi-Fi to Data Collector Method

  1. You can see the status of your internet connection on the Mi-Fi screen:
    With a glance, you know your MiFi device is online.
  2. The Wi-Fi connection from a Surveyor+ to the MiFi is bullet-proof. It just happens and works every time.
  3. You can get a Mi-Fi device from Verizon for use where ATT and TMobile have no service.
  4. Typically the price for a Mi-Fi subscription is lower than a sim card. And because no phone service is associated with the Mi-Fi, there is no tax on the service.
  5. You can use the Mi-Fi with other devices (tablet, laptop, multiple rovers), leveraging the internet service investment.

Disadvantages of Using a SIM Card in a Rover’s Internal Modem

  1. Once you make a connection, you can’t read the signal strength on a ZMax.
  2. Entering all the passwords, user names, server names is a pain in the butt.
  3. The GPS internal modem does not support 3G and 4G connections.
  4. The Data Collector modem does not support 3G and 4G connections.
  5. The card can only be used with one device, unless you remove it which is difficult.

Here is how to make this work:

  1. Connect your data collector to the internet. If you are using a Carlson Surveyor+ (or a Ashtech FT1), turn on internet by clicking on the ‘Wi-Fi’ button in the Wireless Manager:
  2. Follow the on-screen prompts to connect your data collector to an external Mi-Fi internet device. My Mi-Fi device has an ID of ‘IGAGE’:
  3. Start the ‘Internet Explorer’ on your data collector and browse to a website to make sure you are really connected to the internet:
  4. Connect COM2 on the back of the data collector (Surveyor+) to Port B on the back of the ZMax:
  5. Start SurvCE or FAST Survey normally, enter a job.
  6. Connect to your receiver with Bluetooth. (If you are doing a Z-Extreme, you are going to need two serial cables-one for COM1 to PortA and a second for COM2 to PortB.)
  7. Go to EQUIP tab, click on ‘GPS Rover’ button. Check Manufacturer and Model:
  8. Setup Bluetooth or Cable as needed on the Comms tab:
  9. Configure the Receiver tab:
  10. On the RTK tab, choose Device: “Data Collector Internet”:
  11. Click on the hammer/wrench button to right:
    Set the ‘DataCollectorRTKPort:’ to COM2. Click on the green check mark in the upper right corner.
  12. Choose ‘Network:’ as NTRIP, TCP/IP Direct, UDP/IP Direct, NTRIP or SpiderNet as required for your network server:
  13. Click the hammer/wrench button right of the Network and configure your network connection:
    Click on the green check mark. SurvCE will connect to the network and download the mount table. Choose the correct mount point.
  14. Finally click on the ‘GPS Rover’ green check mark to configure the receiver:
  15. After a few seconds, choose appropriate multipath and Ambiguity Fixing:
    Click the green check mark.
  16. If you chose a VRS connection, SurvCE will wait for a GPS reading so your position can be sent back to the VRS server:
  17. After a while, you will see ‘Successful Connection’:
  18. Check to make sure the ‘Correction’ LED (second from left) is blinking green once each second. Those are the corrections being received from your network server.
  19. Your instrument should float, then fix normally.


Filed under Carlson, FAST Survey, Uncategorized

10 responses to “Connecting a Z-Max/Z-Extreme to Network/VRS/DirectIP without a GSM Module

  1. Pingback: MiFi vs. Sim Card | ashgps

  2. Jack Dill

    Thank you for posting this. It. Is. Awesome! I was actively looking for a GSM module for my ZMAX but they are hard to come by. I’m using a Carlson 600+ with only one serial port so I had to use COM1 instead of COM2 for that connection.

  3. Hello, Mark
    This tutorial is great. I want to bypass the GSM module of the Z-Max receiver and connect it to the internet by GPRS (a 3G cellular phone). What I would like to ask you is a step-by-step configuration (ports, cable type, etc.) and also what cable I need to connect the MMCX to Z-Max. The phone will be connected by Bluetooth to MMCX. I use it only as rover.
    Thank you!

    • You are on your own there. I no longer support any connection method other than MiFi to WiFi to Data Collector. Ever. No exceptions. Really.



      • Thanks for the message. What about a USB-type connector 3G modem? Practically is a WiFi hotspot. I need drivers to install it? … because the MMCX did not detect it automatically. Can you help me with that? Thank you! Appologize if I become annoying.

  4. No drivers, no support. Your only option would be Bluetooth which is a PITA.

    There was a specific WiFi adapater that worked with the MMCX, but I don;’t know the part number, I don’t think they are available and I don’t know much about them.

  5. carlos moraila

    I have a old GPS receiver Zxtreme (2000 year to brought), i need a connect this receiver to internet for a base geodetic network, what kind to modem can i connect.

  6. Nice !
    How is it accurate with a rover only and ntrip ? less than 1 meter ? less than 10cm

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