Campbell DCSCOM, Руководство пользователя

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DCSCOM Telephone Modem
The DCSCOM is based around the Dataflex Pocket Stradcom, a commercial BABT-approved
telephone modem. A summary of the features of the DCSCOM is given below.
Features of the DCSCOM include:
•
Initiate and receive calls – full duplex at 1200 baud
•
‘AT’ command set
•
Fitted with BT miniature modular telephone plug
•
Pulse or tone dialling
•
Direct connection to and powered by Campbell Scientific dataloggers using the interface
provided
•
Signal level connects/disconnects 5V DC external power, minimising current drain
The DCSCOM, as configured, fully meets the BABT approval
requirements and responds to the industry standard Hayes ‘AT’
command set.
1. Introduction
The DCSCOM modem is fully Hayes compatible and can be used at 1200 baud to
both receive calls and initiate calls from the datalogger (using instruction 97). For
more information on datalogger programming refer to the description of
Instruction 97 in the datalogger manual.
The DCSCOM is powered from the 5V supply of the datalogger. Current con-
sumption is 0.002mA when off-line and less than 30mA when on-line. The
interface allows the datalogger to switch the power to the modem on and off.
When the modem is switched off, incoming calls are detected by the datalogger
via this interface; the datalogger responds by turning on the modem to answer the
call.
The DCSCOM is connected to a Campbell Scientific datalogger via a special ‘D’
connector interface which plugs directly into the 25-way connector on the modem.
The design of the interface allows other devices (for example a Campbell
Scientific Storage Module) to be connected in parallel with the modem. The other
end of the interface is connected to the datalogger using the 9-pin subminiature
SC12 ribbon cable supplied. The pin-out of the connector is shown in Figure 1.
The pins used by the modem are as shown below. All levels are 0V for logic low,
5V for logic high.
NOTE