Installing the DM24
3 Installing the DM24
3.1 Power supplies
The DM24 accepts power from lines in its
DATA OUT
port. This uses a Güralp
standard ten-pin combined serial/power interface, a cable for which can be obtained
from Güralp Systems, part number CAB-BDA-0036. The serial interface is compatible
with RS232 connections, PC COM ports and serial-to-USB converters. A standard 12
Volt DC power supply is recommended.
3.2 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 beyond unlocking the masses, where appropriate; the
input ports carry sensor power, three 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 – the 'X' channel. This channel is normally digitized
continuously but it is interrupted when you calibrate the instrument so that the
DM24 can return the calibration signal on a stream with a different name, when it
appears as the 'C' channel. When calibration is over, the fourth channel returns to
digitizing the external source.
If you prefer, you can attach any seismometer with a ±10 Volt balanced differential
outputs 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 9.1 on page 121 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 Güralp 6T series of
medium noise instruments or 5-series accelerometers. The four-channel model of
the DM24 (DM24S3) does not have a
SENSOR B
port.
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Issue U - December, 2021
