
3-6
IM WT310E-17EN
Explanation
Handshaking
To use the RS-232 interface to communicate with a PC, the devices on both sides must negotiate a
set of rules to ensure the proper transfer of data. This negotiation is called handshaking. Because
there are many handshaking methods that can be used between this instrument and the PC, you
must make sure that the same method is chosen by both this instrument and the PC.
You can choose any of handshaking methods shown below.
NO-NO, XON-XON, CS-RS
Handshaking
Data Transmission Control
(Sending data to the PC)
Data Reception Control
(Receiving data from the PC)
Software
Handshaking
Hardware
Handshaking
No
handshaking
Software
Handshaking
Hardware
Handshaking
No
handshaking
Stop sending when
X-OFF is received;
resume when X-ON
is received.
Stop sending when
CB (CTS) is false;
resume when it is
true.
Send X-OFF when
the receive buffer is
3/4 full; send X-ON
when it is 1/4 full.
Set CA (RTS) to
false when the
receive buffer is
3/4 full; set CA
(RTS) to it is 1/4
full.
WT
Menu
OFF-OFF
HAnd 0
Yes
Yes
XON-XON
HAnd 1 Yes
Yes
CS-RS
HAnd 2
Yes
Yes
OFF-OFF
Data Transmission Control
There is no handshaking between this instrument and the PC. The “X-OFF” and “X-ON” signals are
treated as data, and the CS signal is ignored.
Data Reception Control
There is no handshaking between this instrument and the PC. When the receive buffer is full,
excessive data is discarded.
RS is fixed to true.
XON-XON
Data Transmission Control
Software handshaking is performed between this instrument and the PC. When this instrument
receives an “X-OFF” code from the PC while it is sending data, it stops the data transmission. It
resumes the operation when it receives a “X-ON” code. The CS signal received from the PC is
ignored.
Data Reception Control
Software handshaking is performed between this instrument and the PC. When the free area of the
receive buffer falls to 64 bytes, this instrument sends an “X-OFF” code to the PC. When the free
area reaches 192 bytes, this instrument sends an “X-ON” code.
RS is fixed to true.
3.4 Configuring the RS-232 Settings of This Instrument