Using the Passive Client To Send Messages |
If your Iguana channel is communicating with an application or server that requests messages, you can use the passive_llp_consumer_plugin plugin to send messages in response to these requests. This plugin is included with Iguana, and is located in the plugins subdirectory of the directory in which Iguana is installed.
 | ||
|
New Feature in Iguana 4.5 passive_llp_consumer_plugin is new in Iguana 4.5. | ||
 |
To create a channel that uses passive_llp_consumer_plugin, do the following:
-
In the Dashboard Control Panel, click Add Channel. - From the Source list box, select the source for your messages.
- From the Destination list box, select To Plugin.
- Click Configure Channel.
- In the Channel name field, type the name of your channel.
- Click the Source tab, and supply the information that is needed to specify the source component of your channel. For test purposes, you can select LLP Listener as the destination, then use the HL7 Simulator to send test messages.
- Click the Destination tab.
- Ensure that the Iguana starts executable check box is selected.
- In the Full executable path text field, type or browse for the complete file path and file name of passive_llp_consumer_plugin. This plugin is normally located in the plugins subdirectory of the directory in which Iguana is installed.
- In the Executable parameters field, type the executable parameters that you want to supply to passive_llp_consumer_plugin. These are described below, and shown in the following illustration:
Setting Up The Channel To Use passive_llp_consumer_plugin
- Click Add Channel to create this channel.
The executable parameters that are supplied to passive_llp_consumer_plugin are, in order:
- The name of the host on which your Iguana server is running;
- The plugin communication port that the Iguana server is using;
- The name of the channel;
- A parameter indicating whether the plugin is communicating with the source or destination component of the channel (in this case, the plugin is always communicating with the destination component, so this parameter should always be set to destination);
- The port on which the plugin will accept connections.
passive_llp_consumer_plugin also accepts the following optional flags, which must be specified before any other parameters:
| Parameter | Description |
|---|---|
| --verbose | Indicates that outgoing messages and incoming ACK messages are to be printed to the standard output file. (To find out how to view the standard output file from Iguana, see Monitoring Plugin Output.) |
| --stop_channel_on_ack_error | Stop the channel if an ACK timeout or an ACK verification error is encountered, or when a connection is lost after a message has been sent but before an ACK has been received. The default behavior is to skip the message. |
| --ack_timeout timeout | The acknowledgment (ACK) timeout. timeout is the value to use as the ACK timeout, specified in milliseconds. If not specified, the default value is 5000. Note that this timeout value must be less than the value specified in the To Plugin destination component's Plugin timeout field. |
| --ack_verification mode | The ACK verification mode. mode must be one of any, none, any_ack or verified_ack (described below). The default is any. |
| --ack_vmd_path path | The VMD file that is to be used for the verification of ACK messages. path specifies the location (path and filename) of this VMD file. If this parameter is not specified, ack_verify.vmd is used. ack_verify.vmd is normally found in the directory in which Iguana is installed. |
If the --ack_verification flag is set, its value must be one of the following:
| Acknowledgment verification | Meaning |
|---|---|
| any | Treat any message sent back by the target machine as a valid acknowledgment. |
| none | Disable waiting for acknowledgment messages. Any acknowledgments received will be ignored and logged to the standard output file. (This option was added to version 4.5.3 of Iguana.) |
| any_ack | Use the VMD file provided in the --ack_vmd_path flag (or ack_verify.vmd, if --ack_vmd_path is not specified) to parse the acknowledgment and ensure that it is an HL7 message of type ACK. Iguana uses the message identity to verify that the acknowledgment is valid. |
| verified_ack | This option provides the strictest acknowledgment checking. The VMD file provided in the --ack_vmd_path flag (or ack_verify.vmd, if --ack_vmd_path is not specified) is used to parse the ACK message and the original message and compare the MessageControlID fields in the MSH segments of the messages. The acknowledgment message must be of type ACK. You can add even more stringent acknowledgment validation by adding fields to the MSH table in the VMD file and mapping them to the fields that you want to compare in the messages. For example, you might want to compare the message type in the acknowledgment message to the message type in the original message. |
If you are running passive_llp_consumer_plugin from within Iguana, and you are using the Executable parameters field to specify its parameters, you can use the keywords $hostname$, $port$, $channel$ and $component$ to specify the first four parameters. For example:
$hostname$ $port$ $channel$ $component$ 9999 |
After you have created your channel, you can test your connection to the receiving application as follows:
- Start the channel. Iguana starts passive_llp_consumer_plugin, and this plugin starts listening on the specified port.
- When Iguana gives a message to the plugin, the plugin checks whether a connection is active. If no active connection exists, the plugin tries again in 5 seconds.
- If an active connection exists, the plugin sends the message to the client, and waits for an ACK.
- When the ACK is received (or a timeout occurs), the plugin returns the result of processing the message to Iguana.
 | ||
|
passive_llp_consumer_plugin is only allowed to have one active connection at a time. New connections are accepted as follows:
| ||
 |