Basic Modem Operation
Modem Configurations for Cellular Operation
The Trumpcard’s performance will be improved by modifying the standard (factory default) configuration. For reliable communications, it is also recommended that the Modem to which you are connecting also be MNP10 compatible. Using a MNP10 link will allow negotiation of the Modem link speeds based on current line conditions.
For a MNP10 to MNP10 link negotiation at 1200 bps the Trumpcard initialization string would be:
| AT&F&C1&D2S95=44)M1*H1:E0 |
| The other Modem, if a landline based Modem, can be initialized with: |
| AT&F&C1&D2S95=44 |
| In this configuration the modems will first establish a MNP10 link at 1200 |
| bps. They will then make a step up to 4800 bps and then step up to a final |
| speed based on the line conditions. The total connect time for this method |
| can be up to 60 seconds. |
| For a MNP10 to MNP10 link negotiation at 4800 bps (quick connect) the |
| Trumpcard initialization string would be: |
| AT&F&C1&D2S95=44)M1*H2:E0. |
| The other Modem if a landline based Modem can be initialized with |
| AT&F&C1&D2S95=44)M1@M18 |
| In this configuration the modems will first establish a MNP10 link at 4800 |
| bps and then step up to a final speed based on the line conditions. The |
| total connect time for this method can be up to 40 seconds. |
| For connecting to modems that do not support MNP10 the Trumpcard |
| initialization string would be |
| AT&F&C1&D2S95=44:E0%E2 |
| which will result in the Trumpcard trying to establish the best possible link |
| speed. If it is found that connections cannot be reliably made, then it may |
| be necessary to force the Trumpcard connection to 4800 bps using the |
| initialization string |
| AT&F&C1&D2S95=44:E0%E2F6. |
Note: | Refer to the [n command for details on how to combine cellular and |
| land based initialization strings. |
User’s Guide and Reference | 4 - 9 |
