YOKOGAWA WT3001E User Manual page 18

2.3 Combination of Handshaking Methods
XON-RS
CS-RS
Precautions Regarding Data Reception Control
2-4
Data Transmission Control
Software handshaking is performed between this instrument and the PC. When an
"X-OFF" code is received while sending data to the PC, this instrument stops the data
transmission. When this instrument receives the next "X-ON" code, this instrument
resumes the data transmission. The CS signal received from the PC is ignored.
Data Reception Control
Hardware handshaking is performed between this instrument and the PC. When the free
area of the receive buffer decreases to 64 bytes, the instrument sets "RS = False." When
the free area increases to 192 bytes, it sets "RS = True."
Data Transmission Control
Hardware handshaking is performed between this instrument and the PC. When the
CS signal becomes False while sending data to the PC, this instrument stops the data
transmission. When the CS signal becomes True, this instrument resumes the data
transmission. The "X-OFF" and "X-ON" signals are treated as data.
Data Reception Control
Hardware handshaking is performed between this instrument and the PC. When the free
area of the receive buffer decreases to 64 bytes, the instrument sets "RS = False." When
the free area increases to 192 bytes, it sets "RS = True."
When handshaking is used to control the reception of data, data may still be sent
from the PC even if the free space in the receive buffer drops below 64 bytes. In this
case, after the receive buffer becomes full, the excess data will be lost, whether or not
handshaking is in effect. Data storage of data resumes when there is free space in the
buffer.
Data Receiving Control using Handshaking
256 bytes
Used
Used
Note
The PC program must be designed so that the received buffers of both this instrument and
the PC do not become full.
Free, 64 bytes
Free, 192 bytes
Used
When handshaking is in use,
reception of data will stop when the
free space in the buffer drops to 64
bytes since data cannot be passed
to the main program fast enough to
keep up with the transmission.
After reception of data stops, data
continues to be passed to the
internal program. Reception of data
starts again when the free space in
the buffer increases to 192 bytes.
Whether handshaking is in use or
not, if the buffer becomes full, any
additional data received is no
longer stored and is lost.
IM WT3001E-17EN