Step 3:
Start controlling your RS-232 devices by using 232Analyzer
232Analyzer
is an Advanced Serial Port (protocol) Analyzer software, which allows
you to control/debug, monitor/sniff serial devices
(RS-232/RS-485/RS-422/TTL) right from your PC.
232Analyzer is a shareware, the FREE
version has some limitation but is more than enough to test and control
your serial devices. Click
here to download a FREE copy.
Checksum calculation
232Analyzer comes with
a Checksum calculator, which allows you to calculate the complicated
checksum byte in seconds, here is an example:
Suppose that you are
controlling a projector, and the projector protocol uses xOR to get the
additional checksum byte, the command string to turn ON the projector
is: "1A 2B 3C" plus the Checksum byte. Use the following procedures to
calculate the Checksum byte:
1. Select Hex as an
operands format
2. Select xOr as an operator
3. Key in the command string and append a comma (,) after each byte of
command code: e.g. 1A,2B,3C,
4. Click on the "Calculate" button and you will get the result of 0D (0
is omitted)
Select COM port and
Setup communication formats
From the toolbar (as
shown above), you can choose the COM port that is connected to the
projector (i.e. Port 5), the Baud rate (i.e. 19200 bps), the Data bit
(i.e. 8), the Parity (i.e. Even) and the Stop bit (i.e. 1).
Note: After you have
set up the correct communication formats (they must match with the
projector's COM port settings), click on the "Connect" button on the
left to activate the COM port.
Setup Flow control
You can set up the flow
control from the window above. It could be either Software (XON/XOFF),
Hardware (RTS/CTS), Both (Software + Hardware), or None.
Control your RS-232
devices
1) Control / Monitor
Line States
232Analyzer allows you
to control / monitor line states of your COM ports.
1. Line states of RTS
and DTR will be toggled when the respective LED is clicked, you can use
a voltage-meter to verify the changes, you should get +6V to +15V when
the line state is ON, and -6V to -15V when the line state is OFF.
2. Other line states can be monitored through the Virtual LEDs, such as
RX, TX, DSR, CTS, DCD and RI.
2) Send / Receive
commands
Use the above example
to control a projector (turn ON the projector), key in the complete
command string "1A,2B,3C,0D," into the Send_Command_Pane as shown above
(note: You need to add a "," sign after each command code), and then
click on the "Send" button...
Congratulations! You
just controlled a RS-232 device by yourself!
Notes:
1) In the FREE version, Hex mode is not available. You can use Decimal
format to send out the command string: "26,43,60,13,"
2) You can use any RS-232 device for testing, as long as you know the
protocol commands.
Step 1: Understand
RS-232 Connections & Signals
Step 2: Learn
about the Protocol
See Also:
ASCII Table - Standard and
Extended ASCII Tables
Real-world example: Pelco-D/P Protocol Tutorial
Monitor RS-232/RS-485/RS-422/TTL communications
Control RS-232/RS-485/RS-422/TTL devices
232Analyzer software features
|
