Working with Memory
Courier 56K Business Modem Command Reference
Working with Memory
This chapter contains information about:
You can upgrade the software held in Flash memory by performing a software download. Refer to the Upgrading your Modem chapter of this guide for more information about performing a software download.
Courier 56K Business Modems contain three types of memory that you can interact with: random access memory (RAM), nonvolatile random access memory (NVRAM), and Flash memory.
Note: To see a complete listing of the permanent settings stored in Flash memory refer to the Flow Control Template appendix in this guide.
Working with RAM and NVRAM
You can change any setting just for the current session. For example, setting your Courier 56K Business Modem to AT&N8 will only allow a connection to a remote devices at a rate of 14400 bps or lower until the modem is reset. Once the modem is reset, the default variable connection rate will be re-established.
If you want the new setting to be a default, write it to NVRAM at the same time. From the example above, you would send AT&N8&W to the modem. The new default setting for your Courier 56K Business Modem will only allow a 14400 bps connection to a remote device.
Note: To restore NVRAM factory defaults, use the AT&Fn command. Refer to the Alphabetic Command Summary chapter of the Appendixes section for more information on setting &Fn.
Example: To store the phone number 555 6789 at position 2, type AT&Z2=5556789. If you want to dial the phone number you saved, type ATDS2.
If the call requires a special setting, insert it in the command before the DSn command. In this example, &M0 (no error control) comes before DS2. Type: AT&M0DS2
CAUTION: The AT&Zn=s command functions differently when Dial Security is enabled. Refer to the Dial Security chapter of this guide for more information.
Displaying S-Register Value Information
Saving a Command String to NVRAM
Programming the Voice/Data switch
After storing a command to NVRAM, you can program the voice/data switch to execute the stored command string when pressed. The function of the voice/data switch is determined by the setting of S-Register 32.
Example: Issuing AT&ZC=I6 to your modem stores the command string that displays the link diagnostic screen to NVRAM. Then issuing the ATS32=9 command to your modem will allow you to display the link diagnostic screen whenever the voice/data switch is pressed.
Example: Sending AT&F1 to your modem will load the Hardware Flow Control Template into RAM Memory.
DIP switch settings override AT commands at power-on. You can set DIP switch 10 to ON and reset the Courier 56K Business Modem to load the &F0 settings.
All of the settings in each template are given in the Flow Control Template appendix in this guide.
For more information about hardware and software flow control, refer to the Flow Control Template appendix in this guide.
Saving Flash Templates to NVRAM
To save one of the three flash templates to NVRAM and have it serve as the reset default, enter AT&Fn&W.
DIP switch settings override AT commands at power on. Make sure DIP switch 10 is OFF, or the &F0 template will be loaded.
When the Courier 56K Business Modem is turned on, it loads the settings stored in NVRAM. By default, these settings are the same as the &F1 template.
You can save any of the three templates, or save modified versions of them, in NVRAM for use as power-on defaults.
Refer to the Flow Control Template appendix in this guide for a complete listing of the default values.