4-20
IM 760201-01E
Explanation
The measurement period is determined by the data update rate (see section 4.9 for
details) and by the synchronization source, which is specified by following the procedure
described in this section. For details, see appendix 6.
During normal measurement, numeric data is measured or computed from the data
sampled within the measurement period.
Setting the Synchronization Source
Only installed elements appear. For each element, you can select which input signal will
be the synchronization source (the measurement period will be synchronized to the zero-
crossing point of the input signal). You can select the synchronization source signal from
the choices listed below. The selectable items vary depending on the installed elements.
When independent element configuration is off, the synchronization source for all
elements in a wiring unit is determined by the synchronization source of the first element
in the wiring unit.
U1, I1, U2, I2, U3, I3, Ext Clk (external clock), and None
Note
If you specify no synchronization source by selecting “None,” all of the sampled data within the
data update interval is used to determine the numeric data. When measuring DC signals, this
method can be used to prevent errors in the detection of the measurement period caused by
noise.
When Setting the Synchronization Source to Ext Clk
Apply a clock signal that meets the following specifications to the external clock input
connector (EXT CLK) on the rear panel.
EXT. CLK
• Ext Clk Specifications
Item
Specification
Connector type
BNC connector
Input level
TTL
Input waveform
50% duty ratio rectangular wave
CAUTION
Applying a voltage outside of the range of 0 to 5 V to the external clock input
connector (EXT CLK) can damage the WT500.
Note
• The synchronized measurement slave setting and the synchronization source Ext Clk
setting cannot be made at the same time because they both use the same connector (see
section 12.6 for information about synchronized measurement).
• To connect a BNC cable to the external clock input/external start signal output connector
(EXT CLK) when a GP-IB cable is connected to the GP-IB connector, first remove the GP-IB
cable. Then connect the BNC cable. Finally, reconnect the GP-IB cable.
4.7 Setting the Measurement Period