Guralp Systems CMG-DM24 - Manual (Page 6)

CMG-DM24
2 Installing the CMG-DM24
2.1 Power supplies
The DM24 accepts power from lines in its DATA OUT port. This is a
Güralp standard 10-pin combined serial/power interface, a cable for
which can be obtained from Güralp Systems. A standard 12V DC
power supply is recommended.
2.2 Connecting sensors
The DM24 is configured for use with Güralp Systems feedback
sensors, which can be connected directly to the SENSOR A and
SENSOR B ports. No further configuration of the sensor is necessary;
the input ports carry sensor power, four channels of differential
velocity, mass position and calibration signals. The AUXILIARY port
allows you to measure and digitize environmental parameters, e.g.
local temperature, pressure, or signals from other scientific
instruments.
In addition, two pins on the AUXILIARY port allow you to input signals
for a fourth, full-rate 24-bit data channel. This channel is digitized
continuously, but is interrupted when you calibrate the instrument, so
that the DM24 can return the calibration signal on a stream with a
different name. When calibration is over, the fourth channel returns to
digitizing the external source.
If you prefer, you can attach any seismometer with balanced
differential output to the signal inputs of the DM24. You will need to
make up a cable to connect the relevant pins of the SENSOR A or B
port to your instrument(s). See Section 8.1, page 113, for details of the
connector used.
If you have only one sensor, you should attach it to the SENSOR A
port, since only this port can be used to send control signals to it (e.g.
mass locking and unlocking). The SENSOR B port can therefore only
be used for sensors which do not require remote control signals, such
as Güralp accelerometers or the CMG-6 series of medium noise
instruments. The 4-channel model of the DM24 does not have a
SENSOR B port.
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