RS232 Serial Data Collection Resources
The following links are to pages useful to some engineers who design serial circuits. The information and products contained on the links may or may not be useful or correct for your application.
Null Modems
9M/M adapter at Mouser
9M/F Phoneix Connector adapter at Mouser
Office Depot, null modem cable
Pinout for RS-232 on DB9
While all 9 pins are listed, most applications only use 3 or 5 of these.
Function Name
Data Terminal Equipment Upstream CPU, PLCin/Out
Pin #
Data Circuit Terminating Equipment Downstream Modems, Peripherals, Dogcatcher Data Logger in/Out
dcd
In
1
Out
RxD
In
2
Out
TxD
Out
3
In
DTR
Out
4
In
Ground
-
5
-
DSR
In
6
Out
RTS
Out
7
In
CTS
In
8
Out
RI
In
9
Out
Here’s a good set of figures for D-sub 9 male and female connectors, as viewed from the pin side (not the cable side).
D-sub 9 Male
D-sub 9 Female
RS-232 Standard
While many companies have taken liberties, an official RS-232 standard does exist. The Telecommunications Industry Association sells it for $165.
The Original Dogcatcher
The original Dogcatcher is a quick and easy serial data logger solution for many applications with the most common RS-232 settings: 9600 baud, 8N1. The Dogcatcher is the most economical choice for use with most scales and many RFID systems.
The Dogcatcher 2
The Dogcatcher 2 is a feature rich serial to USB data logger. The user can select the RS-232 baud rate, enable or disable RTS/CTS handshaking, and configure timestamping. The configuration options on the Dogcatcher 2 serial data logger allow its use with many GPS systems, pressure sensors and automated test systems.
Product
Dogcatcher Features
Rugged housing | Low power | Low profile | Tabs for mounting in your enclosure | Logs to standard USB memory stick | Ready to use out of the box
