Guralp Systems CMG-CD24 - Manual (Page 92)

CMG-CD24
7.2.3 Using an external trigger source
To trigger a digitiser from an external source which provides a
triggering voltage, you merely need to connect the external trigger
voltage to pins U and V of the digitiser as shown above. The voltage
can be anywhere between 4 and 40 V DC as the constant current
circuit protects the LED of the optoisolator.
If the external equipment provides a normally open relay contact, the
digitiser's power supply can be used to activate the trigger input:
•
Connect the common pin of the relay to the positive supply on
pin A.
•
Connect the normally open pin of the relay to the positive
trigger input on pin V.
•
Connect the trigger input return (pin U) to the negative supply
on pin B.
•
Connect the other pins as normal.
92 Issue C