5-9
5-15. RS-232C Control Method
Signals are connected to the RS-232C connector in a
straight format as shown in Table 5-15-1 RS-232C
connection signals. This is because a crossing connec-
tion is provided inside the unit. Communication condi-
tions are set to meet the conditions given in Table 5-15-2.
Table 5-15-3 shows the command list of RS-232C.
When transmitting the command, be always sure to keep
100 ms interval between each command. Moreover, the
process time is required for a while when turning the
power ON/OFF and/or selecting the input mode. So in
such cases, also be always sure to keep enough intervals
between the commands.
Table 5-15-1 RS-232C connection signals
Table 5-15-2 RS-232C communication conditions
Pin No.
2
3
4
5
6
7
8
Item
Communication system
Communication type
Signal name
RXD
TXD
DTR
S. G
DSR
RTS
CTS
Signal content
Receive data
Transmit data
Data terminal ready
Signal ground
Data set ready
Transmission request
Transmission enable
I/O
I
O
O
I
I
O
I
Conditions
Transmission speed 9600 baud, No parity, Data length 8 bit, Stop bit: 1 bit
STX (1 byte) + CMD (3 byte) + ETX (1 byte) = 1 block
STX is 02h, ETX is 03h, CMD is command string (Uppercase character)