Globalstar Product Management – Technical Support

(Reference GSP-1620 Integrator’s Ref Manual, pg 7-18)
By pulling pin#25 of the GSP-1620 DB25 to ground for more than 5 seconds and then allowing the pin to float, you will force a reset of the modem.  The modem will reboot after pin #25 is allowed to float.   The normal condition of Pin 25 is floating.

Note that once the modem has been reset, all AT settings will be returned to their default settings.

Normally, the GSP-1620 does not ever have to be reset.  If a reset is necessary, it is usually because there were multiple previous instances of problems with how the application managed the GSP-1620 power.

We highly recommend that you review the following resources for additional information on how to manage the GSP-1620 so that your product will have maximum stability and reliability.

• GSP-1620 Power Management:   Link here
• Avoiding Erratic GSP-1620 Behavior:    Link here
• AT Initialization Settings Must be Reset Upon Power Cycling:   Link here
• Automated GSP-1620 Configuration for User Devices:  Link here
• GSP-1620 Power – Tech Notes:  Link here

There are many helpful tips in the above articles.  For example, an excerpt from the “GSP-1620 Power Management” posting is as follows:

“. . . One way of resetting the NVRAM upon power-up is to ground the reset pin (pin 25) of the GSP-1620 while the modem is being initially powered, and then release the reset pin.  Using this procedure, the GSP-1620 resets its NVRAM upon every power-up sequence.  Another way to reset the NVRAM is to power up the GSP-1620, deassert all DTR signals so that the GSP-1620 shuts down gracefully, and then re-assert one of the DTRs before proceeding with trying to register the modem on the system. . . .”

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Additional keywords:  resets unstable high reliability power