Pi interface for Siemens Spectrum Power tg (Linux)
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- Navigate this page:
- Automatic startup and shutdown
- Automatic startup on a reboot
- Terminating Background Processes
- Anomalous Background Job Termination
Interface Stop ScriptIn the interface directory, there is a standard script that can be used to stop the interface when it is running in the background. This script is called PISIPowerTG_stop. It will look for a running process with the name PISIPowerTG and send it a terminate signal. When running multiple instances of the interface, the script should be copied and edited so that each copy will only kill the required interface. Automatic startup and shutdownTo simplify the management of the system, the interface is normally configured so that it will automatically start and stop when the other PI processes are started and stopped. This is done with the $PIHOME/bin/sitestart and $PIHOME/bin/sitestop scripts. The pistart and pistop scripts use these scripts for any site-specific commands and are typically used to start and stop the interfaces. Note: Before configuring the sitestart and sitestop scripts, ensure that the interfaces are properly configured and have been manually started and stopped without any problems. To have the interface automatically start when the pistart script is run, append the following to the sitestart script. if [ -x $PIHOME/interfaces/SIPowerTG/PISIPowerTG.sh ]; then cd $PIHOME/interfaces/SIPowerTG $PIHOME/interfaces/SIPowerTG/PISIPowerTG.sh else echo "ERROR - PISIPowerTG.sh not found" fi It will check to see if the interface files are present and if so, it will start the interface. If the file is not found then the script will output an error message. To have the interface stopped when the pistop script is run, append the following to the end of the sitestop script.
This calls the function defined in the script to find the PID of the interface, send a terminate signal to the process and wait for up to 5 minutes for the interface to stop. Sample sitestart and sitestop scripts are included in the install kit and can be copied into the $PIHOME/bin directory.
Terminating Background ProcessesNormally, the PISIPowerTG_stop script can be used to stop the interface process. However, if the script is not working, or you wish to stop a process with a different name, use the following instructions. First, obtain the process id (PID) of the background job. This is done as follows. First execute the command: ps -ef | grep PISIPowerTG which will produce output similar to: powertglocal 2527 1 0 09:24 pts/0 00:00:00 ./PISIPowerTG … The second column is the pid of the process. That is, 2527 is the PID of the PISIPowerTG interface in the example above. The process is then stopped by:
The kill command sends the SIGTERM signal to the interface, causing the exit handler to be invoked. Unless it cannot be avoided, do NOT stop the interface with kill –9 pid. The option -9 causes the SIGKILL signal to be sent to the interface. The exit handler cannot catch this signal. SIGKILL will immediately terminate the process, but the process will not be able to shut down in an orderly manner.
A way of insuring that background processes are not accidentally terminated is to use a shell that does not propagate the terminate signal to background processes. If the ksh, bash or csh shells are used then the Ctrl-C from the foreground will not terminate processes in the background. If the system does not support any of these shells then close the current window or logout immediately after starting the background tasks, the user will not be able to accidentally terminate the job in this manner.
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