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2009-07-04T10:28:41Z

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== Linksys WRTSL54GS ==
[[DSCAlarm:Router|Router Information / Setup]]

== DSCMon[itor] - Web Interface and Binaries ==
[[DSCAlarm:DSCMon|DSCMon]]

== TODOs ==
=== Started ===
*Finish developing dscmon.
*Finish web interface.
*`-> Add color option for zone labels
*Document dsc binaries in the "copy extra" area and the "script" area

=== Completed ===
*<s>Change dscsend to use the dsc.conf file.</s> - Done.
*<s>Have dscmon pass parameters to dsclog.</s> - Done.
*<s>Add code to read a log file in dscmon.</s> - Done, it now uses the /etc/dsc.conf.
*<s>Finish developing dsclog. As now I'm using cat /dev/tts/1 > dsc.log and I don't believe this is a good long term solution.</s> - I have dsclog writing to the log file. It's primitive and will need refactoring later.
*<s>Clean up and document scripts.</s> - Done.
*<s>Fix firewall issue (isn't bocking ssh)</s> - Web interface is stubborn, so I added my drop to the S55knockd script.
*<s>Fix serial communications problem</s> - Ended up being a setup issue, so I changed the S15serial script.
*<s>Finished dscsend to send proper packets to the serial port. It will calculate the proper checksum, etc.</s> - Initial version done.

== IT-100 Information ==

I use the IT-100 to connect to the keybus on the DSC alarm. The IT-100 gives me a RS232 port for bi-directional communications. The docs say that it only uses pins 2, 3, and 5 (Rx = Receive, Tx = Transmit, and SG = Signal Ground). By default, the baud rate is 9600, but it can be changed through the IT-100's protocol. There is no flow control. The settings are as follows:

{| border="1"
! Baud Rate !! Parity !! Data Bits !! Stop Bits !! Hardware Flow Control
|-
| 9600 || None || 8 || 1 || None
|}

== RS232 Information ==

Typical RS232 Pinout:
{| border="1"
! Pin !! Label !! Function
|-
| 1 || DCD || Data Carrier Detect (Modem)
|-
| 2 || Rx/RxD || Receive Line
|-
| 3 || Tx/TxD || Transmit Line
|-
| 4 || DTR || Data Terminal Ready (Flow Control)
|-
| 5 || SG/GND || Signal Ground
|-
| 6 || DSR || Data Set Ready (Flow Control)
|-
| 7 || RTS || Request To Send (Flow Control)
|-
| 8 || CTS || Clear To Send (Flow Control)
|-
| 9 || RI || RI Ring Indicator (Modem)
|}

{| border="1"
! Male Connector !! Female Connector
|-
| [[Image:male_rs232.gif]] || [[Image:female_rs232.gif]]
|}

*A low state is defined as anything =< -3
*A high state is defined as another => +3
*Anything between -3 and +3 is in the dead area

== Communications Problem ==

=== Explanation ===

For some reason, my laptop will communicate with the IT-100 just fine, but my Linksys WRTSL54GS router with a TTL shifter will not communicate to the IT-100. Here's where it gets crazy: I can communicate just fine between the laptop and the Linksys router (still using the TTL shifter). The problem is that I need the Linksys router to communicate with the IT-100.

=== Research ===

Laptop pin states, port is closed.
*Pin 3: Low = -10
*Pin 4: Low = -10
*Pin 7: Low = -10

Laptop pin states, port is open and not connected to anything.
*Pin 3: Low = -10
*Pin 4: High = +10
*Pin 7: High = +10

Laptop pin states, port is open and connected to IT-100.
*Pin 2: Low = -5
*Pin 3: Low = -9
*Pin 4: High = +9
*Pin 6: High = +9
*Pin 7: High = +9
*Pin 8: High = +9

Laptop pin states, port is open and connected to Linksys.
*Pin 1: High = 8
*Pin 2: Low = -5
*Pin 3: Low = -9
*Pin 4: High = +8
*Pin 6: High = +8
*Pin 7: High = +9
*Pin 8: High = +9

Linksys pin states, port is closed.
*Pin 2: Low = -6

Linksys pin states, port is open and not connected to anything.
*Pin 2: Low = -6

Linksys pin states, port is open and connected to IT-100.
*All pins are low. Pin 2 carried about -2 volts, which is in the dead area.

=== Solution ===
I figured out that all I need to do was twist the Rx and Tx lines. Yup, a simple null modem adapter would have solved the issue all a long! I'm only guessing that my laptop worked because either the terminal program or the Belkin USB to Serial adapter was smart enough to switch the lines.

== How to Communicate ==
I've used both minicom and microcom without problems. I haven't figured out how to send "\r\n" with either terminal, but I was able to do it from an echo. I basically ssh into the Linksys router twice (I guess I could use screen and switch back and forth). In one session I type the following:
cat /dev/tts/1

Then in the other session I echo the 001 packet, which asks for the current status, as such:
echo -en "\n00191\r\n" > /dev/tts/1

That's all there was to it!

== How to get COM Settings ==
*setserial -g /dev/tts/*
*cat /proc/tty/driver/serial
*stty -F /dev/tts/1 -a

== Setup COM Port ==
* See the following script: [[DSCAlarm:Router:Scripts#S15serial|S15serial]]

If setup properly then it will look like the following:
<span style="color: green">'''root@orc:~# stty -F /dev/tts/1 -a'''</span>
speed 9600 baud; rows 0; columns 0;
intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = <undef>;
eol2 = <undef>; swtch = <undef>; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R;
werase = ^W; lnext = ^V; flush = ^O; min = 1; time = 5;
-parenb -parodd cs8 -hupcl -cstopb cread clocal -crtscts
ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr -icrnl ixon ixoff
-iuclc -ixany -imaxbel
-opost -olcuc -ocrnl -onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0
ff0
-isig -icanon -iexten -echo -echoe -echok -echonl -noflsh -xcase -tostop
-echoprt -echoctl -echoke

<span style="color: green">'''root@orc:~# cat /proc/tty/driver/serial'''</span>
cat: cat: No such file or directory
serinfo:1.0 driver:5.05c revision:2001-07-08
0: uart:16550A port:B8000300 irq:3 baud:114583 tx:277 rx:0 RTS|DTR
1: uart:16550A port:B8000400 irq:3 baud:9593 tx:0 rx:0 RTS|CTS|DTR|DSR|CD

== Links ==
*[http://www.dsc.com/download.php?t=1&id=10910 IT-100 Data Interface Module v1.0 Developer's Guide]
*[http://www.gnu.org/software/libc/manual GNU C Programming Reference Manual]
*[http://en.wikibooks.org/wiki/C_Programming/Standard_libraries ANSI Libraries]

DSCAlarm - Revision history

Ohayden: /* Links */