Procedures for Reconnecting a Disconnected Data Link
The following procedure should be used to re-establish a data link if the previous connection is unexpectedly terminated, regardless of whether the call termination is caused by:
- User’s processor de-asserts DTR_DP (DTR of the Data_Port)
- The 2-way satellite signal is lost due to problems with sky blockage (truck parks next to your modem), antenna problems, etc.
- Local RF interference
- Any other reason
Monitor the DCD signal on the Data Port (DCD_DP):
- Whenever the GSP-1720 establishes a data connection, the modem will assert DCD on the Data_Port (DCD_DP)
- When the the data link is terminated, the modem will de-assert DCD_DP
When DCD_DP is de-asserted, the attached processor (e.g., data logger) should generally:
- De-assert DTR_DP
- Wait 20 seconds for a graceful closeout of the session
Once the user has de-asserted DTR_DP and the required wait period has expired, either:
- Re-assert DTR_DP, compliant with the steps outlined in the document “GSP-1720 timing requirements” and then re-dial AT#777
- or — Shut down the modem by disconnecting Pin_13 from ground, and allowing it to float.
- NOTE: make sure that your script is compliant with the procedures outlined in the document “GSP-1720 timing requirements”
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Additional keywords: 1720, sdvm