Custom Audio Electronics KPM302III, User Manual

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RS232 SERIAL INTERFACE
Female DB9 connector
J1
1 DCD
2 TX During transmission, takes the values -VRS232 and + VRS232 depending on data
3 RX During reception, takes the values -VRS232 and +VRS232 depending on data
4 DSR
5 GND
6 DTR When +VRS232, device is power on
7 CTS
8 RTS When +VRS232, device is ready to receive data
9 n.c.
Given the presence of the RS232 standard, logic value “0” corresponds to the voltage value +VRS232 (voltage value be-
tween +3Vdc and +15Vdc) and logic value “1” corresponds to the voltage value -VRS232 (voltage value between -3Vdc
and -15Vdc.
The following picture shows an example of connection between the device and a personal computer using a 9 pin RS232
serial connector:
DEVICE PC
DCD
RXD
TXD
GND
DSR
CTS
DTR
TXD
RXD
GND
DTR
RTS
DTR DSR
RTS CTS
D
B9
1
2
3
4
5
6
7
8
9
D
B9
1
2
3
4
5
6
7
8
9
When use a serial cable, we recommend the installation of a ferrite core on the power supply cable.
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