Guralp Systems CMG-5T Compact - Manual (Page 23)

Operator's Guide
For distances up to 10 m, you can connect the sensor outputs using
balanced screened twin lines terminated with a high-impedance
differential input amplifier. The sensor outputs have a nominal
impedance of 47 Ω.
The 5T Compact is normally powered directly from a connected Güralp
digitizer through its signal connector, although you can use a separate 10
– 36 V DC power supply if you wish. An isolated DC–DC converter
installed inside the sensor housing forms the main part of the 5T's power
supply; its filtered outputs provide the ±12 V required to operate the
sensor electronics. The DC–DC converter is protected against polarity
reversal. Optionally, this DC–DC converter can be omitted, in which case
you will need to provide a ±12 V three-way power supply yourself.
The calibration signal and calibration enable inputs are referenced to the
signal ground. If you are using a Güralp digitizer, these lines can be
connected directly to its calibration lines. For “active high” instruments,
you will need to provide a 5 V logic level, referenced to the signal
ground. For “active low” instruments, you can connect these lines to the
signal ground to activate the associated function. See Chapter 3, page
13, for more details.
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