The COM220 is connected to a CSI datalogger by a 9-pin subminiature D cable. This is the same 9-pin CS I/O interface common to all Campbell Scientific dataloggers (except the CR200 series). This is not an RS-232 connection. Appendix B describes the CS I/O interface.
The COM220 can be used as an originate modem at the datalogger site. For non-Pakbus dataloggers (e.g., CR510, CR10X, CR23X), and for older PakBus dataloggers (e.g. CR10XPB, CR23XPB, CR510PB) use Instruction 97 to program the datalogger to originate a call to the computer; refer to your datalogger manual for a detailed description of Instruction 97. For newer Pakbus dataloggers (e.g., CR800, CR1000, CR3000) use the ModemCallback instruction or the DialSequence and DialModem instructions to program the datalogger to originate a call to the computer. Again, refer to your datalogger manual and LoggerNet Help files for detailed descriptions of these instructions. In addition, Appendix A.4 includes sample programs for the P97, ModemCallback, and DialModem instructions.
The COM220 features a built-in speaker to allow monitoring of calling and connection. See Appendix A.2 for the Hayes AT commands that affect the speaker on/off and volume settings.
FIGURE 2. COM220
1.2 Computer Requirements
A Hayes-compatible modem is used at the computer site with Campbell Scientific computer software to call the datalogger attached to the COM220. The computer’s modem must be configured to the proper settings using a set of modem initialization strings in the software program’s pick list.