4-5
IM WT1801-01EN
Synchronization Source (Sync Source)
• When you are measuring analog revolution and torque signals, you can select the element to use as the sync
source from the following options. The available options vary depending on the installed elements.
U1, I1, U2, I2, U3, I3, U4, I4, U5, I5, U6, I6, Ext Clk (external clock),
*
and None
* For the EXT CLK connector specifications, see section 4.3 in the getting started guide, IM WT1801-03EN.
• The measurement period is determined according to the zero-crossing point of the selected synchronization
source. The WT1800 uses the measurement period to measure the analog revolution and torque signals.
If you specify no synchronization source by selecting “None,” all the sampled data within the data update
interval is used to determine the rotating speed and torque.
• When the revolution or torque signal is a pulse signal, its value is the pulse signal period averaged over the
measurement period. The measurement period is determined according to the sync source. If the pulse signal
period does not fit within the measurement period, the previous period is used to determine the measured
value.
• To achieve stable motor efficiency measurements, we recommend that you set the sync source for motor
efficiency measurement to the same
that is set in the fundamental measurement conditions. This
ensures that the measurement period is in sync with the measurement functions, such as those for voltage,
current, and active power.
Pulse Input Range
Set an appropriate range for the maximum and minimum input signal values. For example, when you are
measuring signals for rotating speeds of 120 rpm to 180 rpm and torques of –18 N•m to +18 N•m, set the
rotating speed pulse input range to 100 rpm to 200 rpm, and set the torque pulse input range to –20 N•m to +20
N•m.
Upper and Lower Limits ((Pulse Range Upper, Pulse Range Lower)
You can set the pulse range for each input signal within the following limits.
• Revolution signal: 0.0000 to 99999.9999 (rpm)
• Torque signal:
–10000.0000 to 10000.0000 (N•m)
When the input signal type is pulse, the waveform display lower and upper limits are the values that you set
here.
On models with the D/A output option, the rated D/A output values are as follows.
Revolution and Torque Input Signals
D/A output
Setting for Pulse Range Upper
+5 V
Setting for Pulse Range Upper × (–1)
–5 V
Torque Signal Pulse Rating
When the torque signal type is pulse, refer to the torque meter’s specifications to set its rated positive and
negative values.
Positive and Negative Rated Torque Signal Values (Rated Upper, Rated Lower)
Range:
–10000.0000 to 10000.0000 (N•m)
4 Motor Evaluation Conditions (Option)
