BSR BSR00034, Справочное руководство

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CBX ELECTRICAL CONNECTIONS
43
4
4.2.1 RS232 Interface
The serial interface is used in this case for point-to-point connections; it handles
communication with the host computer and allows both transmission of code data and the
programming of the scanner. This is the default setting.
The following pins are used for RS232 interface connection:
CBX100/500 Function
TX Transmit Data
RX Receive Data
RTS Request To Send
CTS Clear To Send
SGND Signal Ground
It is always advisable to use shielded cables. The overall maximum cable length must be
less than 15 m (49.2 ft).
SGND RXD TXD
CTS RTS
USER INTERFACE
SGND TX RX
RTS CTS
SCANNER
Figure 26 – RS232 Main Interface Connections Using Hardware Handshaking
The RTS and CTS signals control data transmission and synchronize the connected devices.
START
OF
TRANSMISSION
END
OF
TRANSMISSION
+ V
RTS
- V
+ V
TX DATA
- V
+ V
CTS
- V
DATA
TRANSMISSION
DATA
TRANSMISSION
C1 C2 C4 C3 C5
TRANSMISSION
STOPPED
ENABLED
DISABLED
ENABLED
IDLE IDLE
Figure 27 - RS232 Control Signals
If the RTS/CTS handshaking protocol is enabled, the DS4800 activates the RTS output to
indicate a message is to be transmitted. The receiving unit activates the CTS input to enable
the transmission.