KEYENCE Visual KV Series - Manual (Page 332)

7.2 Serial Communication
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Chapter 7 Serial Communication
7.2 Serial Communication
When the KV is connected to a personal computer, the current value or preset value
of timers/counters or contents of data memories in the KV can be loaded to and
modified on the computer.
7.2.1 Command Transmission Procedure
Commands are transmitted from a personal computer to the KV base unit as follows:
■ Transmitting a break signal
A break signal is used to initialize the communication buffer and baud rate setting of
the KV. It is necessary to transmit a break signal of 100 ms or longer to the KV
before starting communication. Another break signal is unnecessary once the
communication is established.
A break signal must have the waveform shown below.
Note 1: For the first serial communication with a personal computer after the KV-
P3E(01) handheld programmer is connected to the KV, or after the "KV IncrediWare
(DOS)" or "LADDER BUILDER for KV" programming support software is evoked, be
sure to transmit a break signal. A break signal is unnecessary at other times.
Note 2: If you cannot transmit a break signal, turn OFF the KV once to initialize the
communication program. After that, restart communication between the KV and the
personal computer.
Note 3: Be sure to stop the communication for 10 ms or longer after transmitting a
break signal.
10 ms or longer
Transmits a command
Transmits communications
start command (CR)
Initialize the communication buffer and
baud rate setting of the KV.
Start communications with the KV.
Transmit a command which instructs the
KV to perform the required operation.
Transmits communications
end command (CQ)
End communications with the KV.
▲
▲
▲
▲
Receive and check the response to the
transmitted command.
Transmits a break signal
Receiving a response
▲
▲
100 ms or longer
+V
-V
SD
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