User’s Manual and UT5320R-SxA Series
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9. Remote Communication
This chapter includes the contents as follows.
Interface Setting of RS-232C
Interface Setting of RS-485
Interface Setting of LAN
9.1 RS-232C Interface Setting
9.1.1 RS-232 Interface
RS-232 is widely used serial communication standard, it’s also called asynchronous serial
communication standard. It’s used to to realize data communication between computers and
peripherals. RS is English abbreviation of “Recommended Standard”, 232 is standard number. The
criterion is officialy published by Electronic Industries Alliance (EIA) in 1969. It requires that each bit
should via a data line to transmit.
But the configuration of most serial ports is usually not strictly based on the RS-232 standard: a 25-
core connector is used in each port (today's computers basically use a 9-core connector). The
common RS-232 signal as shown in the following table.
Table 9-1 Common RS-232 Signal
Signal
Symbol
Pin number of 25-core
connector
Pin number of 9-
core connector
Request to send
RTS
4
7
Clear to send
CTS
5
8
Data set ready
DSR
6
6
Data carrier detect
DCD
8
1
Data terminal ready
DTR
20
4
Transmit data
TXD
2
3
Receive data
RXD
3
2
Ground
GND
7
5
Request to send
RTS
4
7
In addition, there is a minimal subset of RS232, which the connecting way of the instrument.
Table 9-2 Standard Minimum Subset of RS-232
Signal
Symbol
Pin number of 9-core connector
Transmit data
TXD
2
Receive data
RXD
3
Ground
GND
5
