23
usually measured in parallel circuit mode;
Normally, when |Zx| < 10
Ω
, the series circuit mode is selected;
When |Zx| >10k
Ω
, the parallel circuit mode is selected;
When 10
Ω
<|Zx| <10k
Ω
, follow the manufacturer’s recommendation.
Two equivalent circuits can be conversed through some formula, and Q and D
don’t change in different circuits, as shown in table 2-4, where s means series
connection, p means parallel connection.
Q=Xs/Rs, D=Rs/Xs, Xs=1/2
π
FCs=2
π
FLs
Circuit model
Dissipation (D)
Equivalent model
conversion
D=2
π
FLp/Rp=1/Q
Ls=Lp/(1+D
2
)
Rs=RpDP2P/(1+D
2
)
L
D=Rs/2
π
FLs=1/Q
Lp=(1+D
2
)Ls
Rp=(1+D
2
)Rs/D
2
D=1/2
π
FCpRp=1/Q
Cs=(1+D
2
)Cp
Rs=RpDP2P/(1+D
2
)
C
D=2
π
FCsRs=1/Q
Cp=Cs/(1+D
2
)
Rp=Rs(1+D
2
)/D
2
Table 2-4 Circuit Model Conversion
2.3.4 Serial interface
The default setting is “OFF”, which means that serial interface is always in the
state of receiving command (unilateralism). When it is set to “ON”, the
instrument sends measurement state and result through interface at the same
time. If “4-rSC ON” is selected, RS-232C interface is opened, which means that
it is allowed to send measurement result through serial interface (bidirectional).
TH2810B’s serial interface meets the RS-232C DB-9 standard. The serial
interface adopts
asynchronous serial communication bus with fixed baud rate of 19200 bit, the
logic level of ±8V and the maximum transmission distance of 15m. The data
format is as follows:
