iFIX PDB Options

The iFIX PDB Settings tab contains fields that enable you to adjust the behavior between the processing of the iFIX process database (PDB) tags and the server tags. You can access this tab from the Tools/Options menu. The iFIX PDB Settings tab displays in the Options dialog box only if you have iFIX installed on your computer.

The following graphic shows the iFIX PDB Settings tab:

The following fields are available in the iFIX PDB Settings tab. It is recommended that you use the default values for each of these fields. Ensure that your settings meet the requirements of the application being used:

The "Enable Connectivity to iFix PDB" option allows you to turn support of the IFIX PDB interface On or Off. By default this setting will be disabled. Important: If IFIX PDB operation is turned off (disabled), the server will not respond to any request for data by IFIX PDB. If you intend to use the server only as an OPC server, you may want to disable Intellution iFIX PDB operation. By doing so, you can increase the security of your data and improve the overall performance of the server.

Timing - Wait xx seconds before timing out on requests between PDB and Driver – The time you set here represents the amount of time the iFix PDB will wait for a response from an add/remove/read/write request before timing out. If the iFix PDB times out, it will fail the request on behalf of the server. This timeout can occur if the server is busy processing other requests, or if iFix PDB has lost communications with the server. In the case of lost communications, the iFix PDB will automatically re-establish communications with the server so that successive timeouts do not occur.

Valid Range	Default Value
5 to 60 seconds	5 seconds

Enable latched data
Normally, data links in your iFix application will display a series of question marks "????" if a communication failure has occurred. In some cases, you may want to have a value displayed at all times, such as when reports are generated. By enabling latched data, the last value successfully read will be preserved on the screen. This feature is not enabled (unchecked) by default. The Enable Latched Data setting in the server is located in Tools | Options under the iFix PDB tab.

iFIX PDB Read Inactivity
The server can automatically deactivate tags that have not been read by iFix for the time period given here. By doing so, unnecessary polling of the process hardware can be reduced.

When iFIX PDB Read Inactivity feature is enabled, the server will look through its list of tags every 15 seconds, and deactivate any that are idle. A tag is considered idle if iFix has not performed a read request of this tag for at least the time period specified here. Since the server checks for idle tags on a 15 second cycle, a tag may not get set inactive at precisely this time from its last read; it could be up to 15 seconds longer depending on when the last read occurred in the check cycle. If iFix requests data from a tag that has been previously deactivated, the server will reactivate the tag and resume polling the hardware.

By default, this feature is disabled upon install of the driver. However, once this feature is enabled, it becomes applied to all projects. You may specify an idle time of up to 6:23:59:59 (1 week).

Warning: This feature is meant to be used with register tags only and can cause non-register tags to go off scan. To avoid this situation when using this feature, be sure to set the inactivity timer greater than the longest scan time configured in the iFix database.

Format	Valid Range	Default Value
[days:hours:minutes:seconds]	0:00:00:15 to 6:23:59:59	0:00:00:15 (15 seconds)

The time period can also be specified in seconds. For example, you could enter "62". The next time you bring up the page, you will see 0:00:01:02.

Examples

20 seconds	0:00:00:20 or 20
1 minute	0:00:01:00 or 60
1 hour and 30 minutes	0:01:30:00 or 90
2 days	2:00:00:00

Creating Datablocks Inside FIX Applications
You do not have to use the server to define static tag. In fact, it is recommended that you use dynamic tags in FIX Database Manager since iFIX PDB does not support server tag browsing.

To add server items to iFIX Database Manager, you must first complete the following prerequisites:

Create and configure the server project adding channel, device (and item if you are using static tags)
Know the three-letter acronym for the server. For our server/driver, the acronym is IDS (Industrial Data Server).
Configure the server in iFIX SCADA Configuration (look for the acronym IDS).

Refer to the next section for details on entering driver data and datablock addresses in Database Manager.

To enter driver specifications for a database block in FIX Database Manager

Select Add from the Blocks menu in the iFIX Database Manager to add a database block. Database Manager prompts you to select the type of database block.
Select the type of block and click OK. The block's dialog box appears as shown below.

Database Block Dialog Box
Enter a name in the Tag Name field.
Complete the driver fields with the appropriate information for your driver.

I/O Driver Fields

NOTE: The Hardware Options field is not used for this driver.

Specifying the I/O Driver in iFIX Database Manager
The Driver field in Database Manager identifies the I/O driver that the database block accesses. This field accepts your driver's three-letter acronym. The drop-down menu for this field provides the same Configured I/O Driver list as in the SCADA Configuration dialog box of the System Configuration Utility (SCU). For our server, enter IDS in this field.

NOTE: The server must appear in iFIX's SCU's Configured I/O Driver list box in order for Database Manager to recognize the acronym you enter.

For this example we use the dynamic addressing format where R0001 is the actual register address in our device. The I/O address for the driver has the following format:
CHANNEL_NAME.DEVICE_NAME.DEVICE_ADDRESS
Where:

CHANNEL_NAME	Is the protocol or driver used in the server project. This name must match the channel name in the server configuration.
DEVICE_NAME	Is the PLC or other hardware that the server communicates with. This name must match the device name for the specified channel in the server configuration.
DEVICE_ADDRESS OR TAG_NAME	Is an address within the PLC or other hardware device that the server communicates with (dynamic) or is an actual tag name specified in the server (static). NOTE: If tags are static, you must include the full path to the tag name.

Project Startup for iFix
In order to have the startup behavior required by iFix, the OPC Server must begin polling immediately upon connection with iFix. (Other clients initiate polling some time after a connection is made.) To accomplish this, the server maintains a list of validated item IDs that have been referenced by iFix. This data is accumulated as blocks are created in iFix, and saved in an ini file. The ini file will be created by the server and given a name based on the current server project file name (opf file). The ini file will be placed in the same folder as the project file. This is not to be confused with the ServerMain.ini file which contains server settings that are used regardless of project file or client. Whenever iFix makes its initial connection with the server, all items listed in the ini file are set active immediately.

Depending on your application, it may not be important that the server reads all items before SAC processing begins. You may choose to remove certain items from the ini file, or delete the ini file altogether in these cases. If you use AO or DO blocks, which are read by SAC one time only at startup, it is essential that these items be included in the ini file. Also, if you have configured alarms connected with data quality, the relevant items should be in the ini file to ensure that the data has been read, and therefore of good quality, upon SAC startup.

This server feature was added after the initial release of the iFix interface. To create the ini file for an existing iFix project, export your PDB database from the iFix Database Manager, and import it back. You may select "Yes to all" when the "Confirm tag replacement" message box comes up.

Please note that entries in the ini file are not removed when you delete the corresponding block(s) in your iFix project, or change the I/O Address of the block(s). You may find it necessary to manually edit the ini file to remove items that are no longer used, or to recreate the ini file upon completing your PDB database. Reconstruction is the recommended practice. To recreate the file, simply delete it, then export and import your PDB database.

If an item ID listed in the ini file is ever found to be invalid, as would be the case if a static tag in the server is removed, the entry will automatically be removed the next time iFix is connected.

When manually editing the ini file, make sure you update the "Count" record accordingly.

Important: You must configure iFix to delay the start of SAC processing long enough for the server to complete its initial reads of all items listed in the ini file. The default delay of 8 seconds should be sufficient in most situations, but may need to be significantly longer in some cases. You may change this delay by going into "System Configuration", and selecting "Task Configuration". Select "WSACTASK.EXE" and add the command line argument "Dseconds", where "seconds" is the number of seconds you wish to delay SAC processing. Note that command line arguments for WSACKTASK.EXE must not be preceded with the minus sign "-".

Important: In addition to the SAC delay time, you should make sure that the server's "iFix PDB Read Inactivity timeout", described above, is set such that tags will not be deactivated before SAC makes its first read of the data.

Project Startup for iFix
The "iFix PDB Read Inactivity timeout", described above, should be set such that tags will not be deactivated before SAC makes its first read of the data.