Combination Of Handshaking Methods - YOKOGAWA WT3000 User Manual

2.4

Combination of Handshaking Methods

Handshake format Descriptions→
Handshake
Method
The menu of
this instrument
O F F - O F F N O - N O
X O N - X O N X O N - X O N
X O N - R S X O N - R T S
C S - R S C T S - R T S
OFF-OFF
XON-XON
IM 760301-17E
When using the RS-232 interface for transferring data, it is necessary for equipment on
both sides to agree on a set of rules to ensure the proper transfer of data. The set of
rules is called handshaking. Because there are various handshaking methods that can
be used between the WT3000 and the PC, one must make sure that the same method is
chosen by both the WT3000 and the PC.
You can choose any of the four methods in the table below.
Data Sending Control (control
method when sending data to a computer)
Software Hardware
Handshake
Handshake
Sending stops Sending stops
when X-off is when CB(CTS) is
received, and False, and
sending is sending is
resumed resumed when CB
when X-on is is True.
received.
Data Transmission Control
There is no handshaking between the WT3000 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 the WT3000 and the PC. When the received buffer
becomes full, all overflow data are discarded.
RS = True (fixed).
Data Transmission Control
Software handshaking is performed between the WT3000 and the PC. When an "X-
OFF" code is received while sending data to the PC, the WT3000 stops the data
transmission. When the WT3000 receives the next "X-ON" code, the WT3000 resumes
the data transmission. The CS signal received from the PC is ignored.
Data Reception Control
Software handshaking is performed between the WT3000 and the PC. When the free
area of the receive buffer decreases to 64 bytes, the WT3000 sends an "X-OFF" code.
When the free area increases to 192 bytes, it sends an "X-ON" code.
RS = True (fixed).
Data Receiving Control (control
method when receiving data from a computer)
Software
Handshake
Handshake
No X-off is sent CA (RTS) is set to
when received False when
handshake
data buffer received data buffer
becomes 3/4- is only 3/4-full, and
full, and X-on is is set to True when
sent when the received data buffer
received data is only 1/4-full.
buffer is only
1/4-full.
Hardware
No
handshake
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App
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