Sean Quinn ([email protected]) May 8 2016

This script reads timing data from slimtim. Messages are sent over a serial connection (9600 bps) in ASCII text.

This is a Python 2 program. The only dependency is Python 2.7+

In this version, only Python built-in modules are used.

A USB-serial adapter is used to receive data from slimtim. The OS presents this as a symbolic link in /dev/, usually in the order the adapters were conneccted, such as /dev/ttyUSB0.

Since slimtim is sending at 9600 and has some other quirks it is crucial the symbolic link be configured correctly! Generally the default bitrate is 9600, however, we also want to ignore carriage returns. Use the program stty to do this. It can be invoked as stty -F /dev/ttyUSB0 [options] The following tty settings have been used on testing machines in the lab with success

speed 9600 baud; rows 0; columns 0; line = 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 = 0;
-parenb -parodd -cmspar cs8 hupcl -cstopb cread clocal -crtscts
-ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr igncr -icrnl ixon -ixoff
-iuclc -ixany -imaxbel -iutf8
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

Aside from enabling ignore carriage returns, these are mostly defaults.

Run the script from any directory.

python slimtim_daq.py

Two files are generated and updated as long as the program runs. The first is tic_tac_events.txt which is a verbatim copy of all serial messages received from TICTaC apparatus at the SBC.

The second, tic_tac.log lists the GPS timestamp in GPS_SEC.microsecond format for all 4 fold coincidence events. These events will be forwared to Ricardo's SU emulator program to issue a T3 to the south station.

• Add line to issue T3 request

• May 8 2016: Initial program uploaded. Basic functionality.
• May 12 2016: tty config