YOKOGAWA CW140, Руководство пользователя, Страница: 158 / 292

IM CW140-E
15-6
Precautions on Data Receive Control
When the CW140 power meter is controlling receive data by means of a
handshake, additional data may be sent from the computer even if there is
less than 256 bytes of free space in the receive buffer. If the receive buffer
becomes full, all extra data are discarded regardless of the handshake.
When the receive buffer recovers free space, it resumes data storing.
1024 bytes
Used 256 bytes of
free space
In communication based on
handshaking, the meter stops receiving
data if it cannot transfer data internally
fast enough and the buffer's free space
becomes less than 256 bytes.
Used
768 bytes of free space
If the free space increases to 768 bytes
as a result of continuing internal data
transfer, the meter resumes data
receiving.
Used
Regardless of the handshake, all extra
data will be discarded if the buffer
becomes full.
Data Receive Control Using Handshaking
TIP
The program on the personal computer must be designed so that the receive buffers on the meter and
the personal computer do not become full.
15.3 Handshake Methods