Advantech PCI-1625U User Manual

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PCI-1625U User Manual
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5.2  Wiring
Since the RS-232 interface is not strictly defined, many devices have their 
own connection methods, which may ignore some signal lines or define 
reserved lines for other functions. It is best to refer to the user manual of 
your device for installation instructions. You may find the following 
helpful.
In general, DTE (Data Terminal Equipment) refers to the device that is 
leading the communication. Examples include PCs, terminals and some 
printers. DCE refers to the device being communicated with or con-
trolled. Examples include modems, DSU’s (digital service units), printers 
and lab/factory equipment. In some situations, you may be able to get by 
with just three lines: data on RxD, TxD and ground.
Table 5.5: Terminal or PC (DTE) Connections
DB25 Male
DB25 Male or Female: Terminal
Pin
Signal
Pin
Signal
2
TxD
3
RxD
3
RxD
2
TxD
4
RTS
5
CTS
5
CTS
4
RTS
6
DSR
20
DTR
7
GND
7
GND
20
DTR
6
DSR
8
DCD
8
DCD