KEYENCE Visual KV Series - Manual (Page 279)

7.5 KV Mode Programming KV-300 Series Only
KV
-300
KV-10/80
Chapter 7 KV-L2 Serial Interface Module
1-255
1
7
7.5.2 Serial Communications Procedure
The KV-L2 can be connected to a personal computer to read the current values and
set values of the counters and timers or the data memory values into the PC from
the KV-300 CPU for checking or updating.
Command transmission procedure
Commands are transmitted from a personal computer to the KV-L2 as follows:
Break signal
Upon receiving a break signal, the KV-L2 initializes its own communications buffer
and baud rate. The break signal should be transmitted only once before communica-
tion is initiated. The break signal need not be transmitted once communication is
successful.
The break signal must have the waveform shown below.
Note: Transmit the break signal for the first communication with a personal com-
puter after the KV IncrediWare (DOS) has been activated through a KV-L2 or KV-
P3E.
If transmission of the break signal fails, turn OFF the KV-300 CPU power switch to
initialize the communications program. Then begin communicating with the personal
computer.
Command
Response
KV-300
CPU
KV-L2 PC
Initializes communications
program in the KV-300 CPU.
1
2
3
4
5
Transmits a break signal (100 ms or longer)
Transmits communication start command (CR)
Transmits a command
Receives a response
Transmits communication end command (CQ)
Starts communications with the
KV-300 CPU.
Transmits a command that
instructs the KV-300 CPU to
perform a required operation.
Checks a response to the
required operation.
Terminates communication
with the KV-300 CPU.
+V
-V
SD
100 ms min.
KVHKA Chap 07_5to10.p65 08.3.11, 11:18 AM 255