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Appendix A. Advanced Topics
Appendix A.1. Separating Data Streams.
The driver processes the ASCII stream and stores the converted data when the stream ends. By default the driver closes the stream when it receives the CR character (Hex code = 0x0d Decimal code = 13).
The default end of stream character can be changed using the registry.
The example below is an extract from registry.ini. The Registry group is for port P1. Similar groups can exist for other ports and a group may have more settings than those shown below. If you wished to change the end of stream character to a NEW LINE character (Hex=0x0a Decimal=10) then change the 13’s to 10’s in the example below. The default_ value is used by the registry when it receives a ‘restore defaults’ command.
[FieldServer_P1] Termination_Char = 13 default_Termination_Char = 13
Appendix A.2. Interaction with the WebServer Driver
This driver is specially configured to watch for registry changes that are initiated from the WebServer driver. It is possible to configure the connection settings of the port without changing the configuration file as follows:
•Create web pages to change the registry settings.
•Browse to the web page.
•Change a setting.
•When the WebServer sees that the new settings have been updated it sets a signal for the ASCII driver to use the new settings.
The html fragment below can be inserted in a Web Page. It will allow a user via a browser to change the connection settings for P1.
<FST_COMBOReg_name="FieldServer_P1:Baud" List_Items="300;600;1200;2400;4800;9600;19200;38400;115200;">
<FST_TEXT Reg_name = "FieldServer_P1:Data_Bits" >
<FST_TEXT Reg_name = "FieldServer_P1:Stop_Bits" >
<FST_TEXT Reg_name = "FieldServer_P1:Parity" >
You can add a similar field for any parameter in the registry file but note that only some registry settings are used by this driver and only some drivers (including this one) are designed to be notified of a change and will work with the changed data.
Using this interface you can deliver a system which a customer can simply use to adjust the connection settings without learning how to configure a FieldServer. Ensure that registry.ini is installed on the FieldServer.
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