Campbell Scientific LoggerNet Datalogger Support Software - Manual (Page 468)

Section 14. Troubleshooting Guide
Dataloggers
The example above shows a terminal emulation session with a datalogger.
Once you have selected the datalogger click Open Terminal to start
communications. Array-based dataloggers require you to type in the letters 7H
(2178H for CR7 and 21X) and press Enter to establish terminal emulation
mode. Table-based dataloggers are ready for terminal emulation when they are
first selected. Just press Enter. For a definition of commands that are available
in terminal emulation mode see the datalogger operators manual or prompt
sheet. On CR5000 dataloggers type H when the prompt comes up and a list of
options will be displayed.
Use caution while in terminal emulation mode. You can change
or disable operation of the datalogger with these commands.
ComPort
You can use the Terminal Emulator to perform a communications test on a
ComPort. To perform a feedback test, select the ComPort and click Open
Terminal. Then connect the Transmit and Receive lines (2 and 3) of the serial
port cable using a small screw driver or paper clip. Click in the window to get
the cursor and type some characters on the computer keyboard. If the
characters are echoed back to the screen, the ComPort is working.
The characters on the screen can be cleared by clicking Clear.
Phone Modems
Selecting a phone modem and clicking Open Terminal will allow you to send
ASCII characters to the phone modem. This can also be used to test
communications to the phone modem and the initialization strings used to set
up and configure it. Get the information for the available commands and
format from the modem manufacturer.
An example of how to troubleshoot a datalogger on a phone link might follow
this sequence.
Say that you cannot communicate with a datalogger and you don’t hear the
phone modem dial the number. You could wonder if you are using the correct
COM port. Disconnect the serial cable from the phone modem, select the
COM port, and click Open Terminal. Then, shorting pins 2 and 3 at the end of
the serial cable, type characters and, if you’ve chosen the correct COM port,
you should see those characters echoed to the screen. (Note: the RS232
protocol allows any pins on a cable to be shorted without damaging the
computer. Pins 2 and 3 are the second and third pins from the upper left on the
top row when looking at the male end of the cable, with the long row of pins on
top. This is true for either 9-pin or 25-pin cables.)
Once you have established that you have the correct COM port, you may hear
the modem dialing, but the datalogger doesn’t connect. Perhaps the modem is
not dialing correctly or using an appropriate initialization string. You can work
with the modem by selecting it in Terminal Emulator and clicking Open
Terminal. LoggerNet will open the COM port and raise DTR to enable the
modem. You can then type characters to be sent to the modem. For example,
NOTE
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