Note: You don’t have to mess with any of the internal register settings for the modes listed below! Note that the configurations described below have been tested on domestic phone lines. They may need some tweaking for international or noisy phone connections.
The configuration described below assumes that a mgetty process has been set up on the remote machine to listen for calls through the serial port connected to the phone modem. It is not necessary to configure the point-to-point protocol (PPP) if all is needed is remote login capability (using a dumb terminal connection) with no file transfer required. However, PPP is necessary to emulate a true TCP/IP connection (for telnet or ftp applications ) through the serial port. Please refer to the HOWTO.2 and HOWTO.3 notes for details on how to install mgetty and PPP.
This configuration requires standard DB25-DB9 serial cables (null) between each modem and the computer to which it is attached.
Both the dial-out and dial-in modems must load the hardware flow control template when first turned on, i.e. dip switch 10 is off to load the factory default NVRAM &F1 template at power-on. However, if for any reason, you suspect that the NVRAM defaults have been been modified, you must reset the template to its default values by using the Linux communication program to issue the command at&F1&W (this overwrites the “modified” &F1 template with the factory default &F1 settings). Then, power-cycle the modem and the default settings will take effect. Both local and remote modems should be configured identically.
The dial-in (remote) modem does not need to have auto answer turned on. The getty program running on the remote server is already listening to the port and will force the modem to answer when an incoming call is detected. However, having auto-answer on should not pose a problem either.
The following switch settings have been shown to work!
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | |
| OFF | X | X | X | X | X | X | ||||
| ON | X | X | X | X |
Used to query/program/download a Trimble receiver with RFILE (Linux version number unavailable), or download with LAPDOGS v.2.0_BETA.
Settings:
This configuration requires a standard DB25-DB9 serial (null) cable between the local modem and the base computer, and a Trimble remote download cable type 21295 between the remote modem and receiver.
Both the dial-out and dial-in modems must load the no-hardware flow control template when first turned on, ie. make sure that dip switch 10 is on to load the &F0 template at power-on.
The dial-in (remote) modem must have auto answer turned on, i.e make sure dip switch 5 must be in the off position (don’t ask why!) to have auto-answer on. Confirm this by making sure the AA (auto-answer) light is on.
The following switch settings have been shown to work!
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | |
| OFF | X | X | X | X | X | |||||
| ON | X | X | X | X | X |
Notes:
Use the –Matdt phone-string option with any rfile command to query the Trimble receiver on the fly. To test LAPDOGS, check /Data directory and log file in /Logs to confirm download . Note that if only one file is found on the receiver, LAPDOGS will not download it!! If the link is non-functional, a time-out will occur after 30 seconds (issued by rfile).
Used to log on to AOA Turborogue receiver to query/program/download receiver, or to download with GNEX.
Settings:
This configuration requires a standard DB25-DB9 serial (null) cable between the local modem and the base computer, and a serial DB9-DB9 null cable between the remote modem and the receiver.
Both the dial-out and dial-in modems must load the no-hardware flow control template when first turned on, ie. make sure that dip switch 10 is on to load the &F0 template at power-on.
The dial-in (remote) modem must have auto answer turned on, i.e make sure dip switch 5 must be in the off position (don’t ask why!) to have auto-answer on. Confirm this by making sure the AA (auto-answer) light is on.
The following switch settings have been shown to work!
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | |
| OFF | X | X | X | X | X | |||||
| ON | X | X | X | X | X |
Notes:
Issue the command cu –l /dev/ttyS# -s 19200 and then type the command atdt phone-string to query or download the Turborogue on the fly. It may be necessary to press <enter> once or twice after a successful connection is established to get the Turborogue to send a login prompt. For GNEX automated downloads, make sure the file modem.pl has a patch for a Courier modem connection (look for modem.pl.fix in the same directory as modem.pl).
Used to query/program/download a Trimble receiver with RFILE (Linux version number unavailable), or download with LAPDOGS v.2.0_BETA.
Settings:
This configuration requires a standard DB9-DB9 serial (direct) cable between the local modem and the base computer, and a Trimble remote download cable type 21295 between the remote modem and receiver.
Make sure the baud rate setting for the serial port of the receiver matches that of the remote radio modem to which it is connected.
Notes:
For a direct access point-endpoint connection (mode 0) leave out the –Matdt phone-string option from the rfile command line to query the Trimble receiver on the fly. To test LAPDOGS, check /Data directory and log file in /Logs to confirm download . Note that if only one file is found on the receiver, LAPDOGS will not download it!! If the link is non-functional, a time-out will occur after 30 seconds (issued by rfile).
For mode 6, not use RFILE directly since the –Matdt option does not recognize the switchable access point-endpoint option. Use LAPDOGS to make sure that the DTR is dropped properly and the base modem is left in a master/switchable mode after both a successful and non-successful connection. In the xxx.site file, make sure to use the appropriate string when prompted for the modem dialstring (e.g. ATDT4 for the position in the call book to call, or ATD5716909 for the specific modem serial number to call)
Used to query/program/download a Trimble receiver with RFILE, or download with LAPDOGS.
Settings:
This configuration requires a Trimble remote download cable type 18827 between the computer and the receiver.
Notes:
Use the –Matdt phone-string option with any rfile command to query the Trimble receiver on the fly. To test LAPDOGS, check /Data directory and log file in /Logs to confirm download . Note that if only one file is found on the receiver, LAPDOGS will not download it!! If the link is non-functional, a time-out will occur after 30 seconds (issued by rfile).
Used to log on to AOA Turborogue receiver to query/program/download receiver, or to download with GNEX.
Settings:
This configuration requires a DB-9-DB9 null-modem cable between the computer and the receiver.
Notes:
Issue the command cu –l /dev/ttyS# -s 19200 and then type the command atdt phone-string to query or download the Turborogue on the fly. It may be necessary to press <enter> once or twice after a successful connection is established to get the Turborogue to send a login prompt. For GNEX automated downloads, make sure the file modem.pl has a patch for a Courier modem connection (look for modem.pl.fix in the same directory as modem.pl).
if you get a message such as “device busy” or “access denied” when starting the communication program, make sure that permissions are set properly on the device file you are using for the connection (i.e. /dev/ttyS#). From root, issue the command chmod a+rw /dev/ttyS#. For dial-out access, you should not use a port which is being monitored by a getty process checking for incoming calls. The getty progam controls the port it is listening to, and periodically resets permissions on the device file associate with the port.
if, despite above fixes, the port remains inaccessible, see HOWTO.5 for possible IRQ conflicts.
Article ID: 265
Created: January 16, 2009
Last Updated: June 19, 2020
Author: Beth Bartel
Online URL: https://kb.unavco.org/article/how-to-configure-a-courier-v-everything-33-6-modem-for-various-data-transfer-modes-via-a-linux-box-265.html