Svantek SVAN 979, User Manual

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SVAN 979 User Manual - Appendixes
1.1 Direct
– when this option is selected, the measured signal from the measurement channel is fed to
the pin 2 of the I/O connector. Output voltage, frequency band and the output impedance are
following:
a) Output Voltage:
1) In the Vibration Meter and Direct Vibration modes, the output voltage is equal to 1.0 V
RMS
(

5 %) at 177 dB indication of the instrument, on High measurement range and at 160 dB
indication of the instrument on Low measurement range, when calibration factor is set to
0.0 dB.
2) In the Sound Meter mode, the output voltage is equal to 70.7 mV
RMS
(

5 %) at 114 dB
reference level of the instrument, when the calibration factor is set to 0.0 dB.
3) In the Direct Sound mode, the output voltage is equal to 1.0 V
RMS
(

5 %) at 137 dB
indication of the instrument, on High measurement range and at 120 dB indication of the
instrument on Low measurement range, when calibration factor is set to 0,0 dB.
b) Frequency Band (-3 dB): 1.0 Hz
÷ 22.6 kHz.
c) Output Impedance: 51
Ω / 5%
1.2. D/A
– when this option is selected, the analogue signal from the internal signal generator of the
instrument after digital-to-analogue converter is transmitted to the pin 1 of the I/O connector, and the
analogue input signal is transmitted to the pin 2 of the I/O connector after digital-to-analogue
converter.
2. I/O Mode: Digital In . When the Ext. Trigger function is active, the external triggering of the instrument
may be provided. To do this, select Trigger: External ( path: <Menu> / Measurement / Measurement
Trigger ). The external signal for triggering is specified as follows:
a) Trigger voltage threshold level is set to +1 V.
b) Trigger voltage slope ( path: <Menu> / Measurement / Measurement Trigger ) set by the user as
Slope [+] (uprising as default) or Slope [
–]
(falling, auxiliary).
c) Minimal duration of the trigger impulse: 10
μsec.
d) 100
μsec. release time after previous measurement is necessary before next trigger.
e)
Recommended trigger voltage should not exceed ± 5 V.
f) Input impedance in the Digital In mode
– ca. 10 kΩ / 100 pF, ESD type safety.
g) When the instrument is switched-off in the Digital In mode, the voltage impulse on the pin [2] will
be able to switch-on the instrument, however in this case the minimal duration of the trigger
impulse of 100 msec is necessary, with uprising voltage slope.
3. I/O Mode: Digital Out . Two different functions are available in this mode:
3.1. Function: Trigger Pulse . When this function is selected, the terminal [2] is set as output, which
enables one to trigger another instrument (one instrument or more with trigger inputs connected
together in parallel), output trigger impulse meets specification given below:
a) trigger impulse is generated before every measurement,
b) output voltage range from 0 V to 3 V,
c) triggering slope: uprising,
d) output impedance: 51
Ω,
e) duration of the impulse: ca. 40
μsec.
3.2. Function: Alarm Pulse . When this function is selected, the terminal [2] is set as an output,
which changes its output level, when current result of measurement exceeds user-
programmable threshold level. In this case the terminal [2] output operates as an output of
analogue comparator with user-programmable threshold. This feature enables one to control an
external device as alarm-indicator or similar:
a) electrical specification of this output are as follows: 0 V to 3 V voltage range, 51
Ω output
impedance,
b) output produces a voltage level (not impulse),