If you have specified From Plugin as the source component for your channel, the Source screen for this channel definition enables you to configure this source component.

	In versions of Iguana that are older than Iguana 4.0, the From Plugin source component is known as the From Client Executable source component.

To configure the From Plugin source component:

• Select the Iguana starts executable check box to start the plugin when the channel is started and shut it down when the channel is stopped. If this check box is not selected, the channel waits for a connection from the plugin.

	If Iguana starts executable is not selected, the Full executable path, Working directory, Executable parameters, Startup timeout and Shutdown timeout fields disappear. The values that you have typed into these fields are preserved. If Iguana starts executable is selected, you can monitor the plugin output while the channel is running. See Monitoring Plugin Output for more details.

• In the Full executable path field, type or browse for the location of the plugin to be run. When you supply the file path for the plugin, its absolute path is displayed:

To include the value of an environment variable in the file path, use ${name}, where name is the name of the environment variable that you have defined. For example, the file path ${MYDIR}\myfile.exe includes the value of the MYDIR environment variable.

The iguana_dir environment variable, which is defined by Iguana, is set to be the location of the Iguana configuration directory. To include this directory in your file path, specify ${iguana_dir} as part of the path.

• From the Working directory list box, select Use executable directory if the working directory and the executable directory are the same. Select Use alternate directory if your working directory is not the executable directory.

• If you have selected Use alternate directory from the Working directory list box, a text field appears. In this text field, type the complete path of the working directory.

• In the Executable parameters field, type any parameters that you want to supply to the plugin when it is started. The default parameters are the macros $hostname$, $port$, $channel$ and $component$, which are described in the table below. If you have changed the parameters and want to go back to using these defaults, click Use Defaults.

The following table lists the macros that can be included as executable parameters:

To include the value of an environment variable in the Executable parameters field, use ${name}, where name is the name of the environment variable that you have defined. If you include an environment variable, a preview field appears that displays the value of the field after the environment variable is replaced by its value:

• In the Startup timeout field, type the time, in milliseconds, that Iguana will wait for a connection from the plugin after it has been started. After this time has elapsed, an error is logged and the plugin is terminated.
• In the Shutdown timeout field, type the time, in milliseconds, that Iguana will wait for the plugin to be shut down after a shutdown request has been issued. After this time has elapsed, an error is logged and the plugin is terminated.
• In the Polling time field, type the polling time in milliseconds. This is the amount of time between attempts to obtain a message from the plugin if no message was found at the last attempt. If a message is found, it is processed, and the next attempt happens immediately after that. This polling time must be at least 10 milliseconds.
• In the Plugin timeout field, type the length of time, in milliseconds, to wait after an event is sent to the plugin before an error is logged.

	For information on how to write a plugin that communicates with Iguana, see Writing a Plugin.