ES51998(60000counts)
DMM Analog front end/Insulation
2.8 Frequency/duty cycle mode measurement
The default typical input impedance of frequency with duty cycle mode is 1MΩ. The MPU
could set control bit RP=1 to change the input impedance down to 100kΩ. MPU send write
command to select the frequency/duty cycle measurement function.
F3
F2
F1
F0
Measurement mode
Read data bytes
0
1
1
1
Hz + Duty mode
D0(0:18), D2(0:18), D3(0:18)
Note1: D0/D2/D3 all are binary format. ASIGN bit is ignored.
Note2: Set LPF1 = 1 to enable the smooth function for sine wave input automatically
Range control for frequency mode
FQ2 FQ1 FQ0
Full Scale
60.000Hz
600.00Hz
6.0000KHz
60.000KHz
600.00KHz
6.0000MHz
60.000MHz
0
0
0
0
1
1
1
0
0
1
1
0
0
1
0
1
0
1
0
1
0
Available minimum frequency input FMIN = 4.000Hz
Frequency & duty cycle mode computed by D0/D2/D3 (if F_FIN=1)
Flag
Range*
STA0=0
STA0=1
STA1=1
STA1=0
60.000Hz
600.00Hz
FREQ=1000000000/D3 FREQ=4000000000/D3 FREQ=8000000000/D3
FREQ=100000000/D3 FREQ=400000000/D3 FREQ=1600000000/D3**
6.0000KHz FREQ=20000000/D3
60.000KHz FREQ=2000000/D3
600.00KHz
FREQ=320000000/D3 FREQ=2560000000/D3***
FREQ=256000000/D3 FREQ=2048000000/D3
6.0000MHz
FREQ = D0-1
60.000MHz
*Note: The Hz measurement of AC+Hz mode is recommended to support 6000 counts displayed
**Note: If D3 < 40000, simple arithmetic mean is necessary to get the 0.01Hz resolution
***Note: If D3 < 50000, simple arithmetic mean is necessary to get the 0.0001 KHz resolution
ver. 1.7
20
12/01/12
CYRUSTEK [ Cyrustek corporation ]
