Campbell Scientific COM200 Telephone Modem - Manual (Page 7)

1
COM200 Telephone Modem
1. Introduction
1.1 General Description
The COM200 Modem is a 9600/1200 baud modem employing the Hayes AT
command set. Its primary use is as a remote site modem connected to a CSI
datalogger. The modem is powered and enabled by the battery-powered
datalogger. When not active, the COM200 draws less than 120
µ
A from the
datalogger’s 12 VDC output.
The COM200 is connected to a CSI datalogger by using a 9-pin subminiature
D connector cable. This is the same 9-pin CS I/O connection common to all
Campbell Scientific products. This is not an RS-232 connection. Appendix B
describes the configuration of this connector.
The COM200 can be used as an originate modem at the datalogger site. To
originate a call to the computer, the datalogger is programmed using
Instruction 97. Instruction 97 is described in detail in the datalogger manual.
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 COM200.
The computer’s modem must be configured to the proper settings using the
modem initialization strings listed in the software programs.
To communicate at 9600 baud, the calling modem’s error correction must be
enabled. If your modem initialization string has an &Q0, you will need to
change it to an &Q5 in order to enable the error correction. You must
continue to use your old string for any communication at 1200 baud.
2. Specifications
•
Bell 212A, CCITT V.22, and CCITT V.32 compatible
•
Full duplex at 9600 and 1200 baud to datalogger
•
V.42 LAPM and MNP2-4 error correction
•
Hayes AT command set
•
RJ-11C telephone jack
•
FCC and IC (formally known as DOC) approval
•
Pulse or tone dialing