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Chapter 4 Command
4.1 TH1778A RS232 Instruction
As the most serial ports, TH1778 is not based on RS-232 strictly, only a min. subset. As figure
：
Signal
Abbr.
Pin No.
Send data
TXD
3
Receive data
RXD
2
Ground
GND
5
The connection between instrument and PC
：
RXD(2)
PC
TXD(3)
GND(5)
(2)
RXD
TH1778A
(3)
TXD
(5) GND
As can be seen from the figure above, the serial port connecting line needs to be crossed, so please be aware of it
when purchasing it. Users can also buy the serial port cable from Tonghui.
4.2 SCPI Command
Note that all the following command are sent and received as strings. Each command must be followed by a
terminator, or the instrument will remain in a waiting state and not process the command. The ending character is
a newline character which is LF. It’s ASC code is 10 in decimal or 0A in hexadecimal. When there is data return,
each data is terminated with LF.
4.2.1 General command set
*IDN?
Function: Check the model, and edition.
Command Format: *IDN?
Command Example:
Input Command: *IDN?
Returned Info: TH1778A, Ver 1.00
*STA
Function: Turn on the instrument and output current
