PPP Configuration

Use these settings to change the receiver PPP (Point-to-Point Protocol) configuration, which is used to make Internet connections through Bluetooth wireless technology or a wired serial connection.

Port – Indicates which receiver port the PPP connection is to be established on.

State – Indicates if a PPP connection is currently connected.

Auto Restart – Select this check box to have the receiver automatically re-establish the PPP connection if it is dropped.

Startup script type – Select a startup script for the receiver. The script is sent to the PPP CHAP (Challenge Handshake Authentication Protocol) program so that user names and passwords can be checked. 

Enable CPIN Check - This check box becomes available when you select the External modem script option from the Startup script type list. Checks and verifies that the CPIN defined in the Advanced Settings is valid for the SIM being used in the external modem.

Use External Modem Default - This check box becomes available when you select the External modem script option from the Startup script type list. When this check box is selected, the dial string uses “ATD*99#” and will not use any value set in the init string. The “ATD*99#” dial string forces the PPP to use the external modem’s default settings, which the receiver does not know.

Use Int/Dial string - This check box becomes available when you select either the GPRS script option or the External modem script option from the Startup script type list. When this check box is selected, you can manually enter the Modem Init string and the Modem Dial string as supplied by the carrier.

Modem Init. String – Enter the initialization string required by the modem. This string contains APN information. By default, it is the Windows “clientclient”. However, for the GSM/GPRS Modem port, the Init String is similar to the following example:

Modem Dial String – Enter the dial string required by the modem. Normally, you use the default setting “ATD*99***2#” where 2 in this string is matched with the 2 in “Modem Init String”.

Use Trimble APN Database - This check box becomes available when you select either the GPRS script option or the External modem script option from the Startup script type list. The SPS Modular receiver firmware contains a database of known carriers with associated Modem Init and Modem Dial strings, which you can select by Country, Provider, and Service plan. This database is updated with new carrier information at each firmware release.

Access Point Name - The APN can be entered manually or generated by using the Trimble APN Database.

CID - Caller Identification. Should be in the range (1-2). The default is 2.

Username – Enter the username (if required) to log on to the carrier network that the modem connects to.

Password – Enter the password (if required) to log on to the carrier network that the modem connects to.

Verify Password – Re-enter the password (if required).

See advanced settings – Select this check box to view and change advanced settings.


Default Local Address – Enter the IP address that is assigned to the receiver when a PPP connection is established.

Default Remote Address – Enter the IP address that is assigned to the remote device when a PPP connection is established.

DNS Address – Enter the default DNS IP Address.

Refuse PAP – By default, this check box is not selected. If it is selected, no PAP (Password Authentication Protocol) is enforced in the system.

Refuse CHAP – By default, this check box is not selected. If it is selected, the system does not use CHAP (Challenge Handshake Authentication Protocol).

Enable ACCM negotiation – ACCM (Asynchronous Control Character Map) is one of the LCP-negotiated options within the CONFREQ frame. ACCM sets the character escape sequences, which tells the port to ignore specified control characters within the data stream. If the router at the other end of the connection does not support ACCM negotiation, the port is forced to use FFFFFFFF. By default, this check box is selected.

Enable ACCM configuration – ACCM Configuration is one of options in PPP LCP layer, and allows LCP Configure-Ack to do ACCM mapping. By default, this check box is not selected.

Max idle time [minutes] – The PPP connection is dropped after this length of idle time.   

Max connect time [minutes] – The PPP connection is dropped after this amount of connection time. If it is set to 0, the maximum connection time is not limited. That is, there is an infinite connection time.

CPIN – SIM PIN (Personal Identification Number). The GSM/GPRS Modem has a SIM card. For some European countries, before dialing, a PIN is required for the modem. The CPIN has a value of 4 to 8 digits, if required. If a user tries to make a PPP connection before the SIM PIN code is confirmed, it refuses the “ATD” command with an error. However, after three unsuccessful attempts to enter the PIN, the PUK (Personal Unblocking Key) is required to force the user to entera new PIN code.

Verify CPIN – Re-enter the SIM PIN code to verify the digits entered in the CPIN field.


Save – Saves the configuration into the receiver's Application File (Appfile) without attempting to make a PPP connection.

Connect – Starts the PPP connection based on the above configuration and saves any changes to the receiver's Appfile.

Disconnect – Disconnects any PPP connection.

Go Back To Defaults – Sets the port configuration to its default settings.


Last Modified: April 5, 2011