IDEC WindSRV - Manual (Page 118)

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KEPServerEX5 Help
What is the Alias Map?
Note 1: For possible additional syntax, refer to the DDE client's specific help documentation.
Note 2: For information on how to connect to remote applications using DDE, refer to
Using Net DDE Across a
Network .
How To... Use Net DDE Across a Network
DDE provides a way to share data between Windows applications as long as they exist on the same machine. Net DDE
shares data from a DDE server located on a local PC with DDE client applications located on remote PCs. More
information on how to configure a PC to support Net DDE is available online.
How To... Use Dynamic Tag Addressing
This server can also be used to dynamically reference a physical device data address from the server. The server will
dynamically create a tag for requested item. Users cannot browse for tags from one client that were dynamically added
by another. Before adding tags dynamically, users should note the following.
 The correct syntax must be used for the data address. For more information on the specific driver's syntax, refer
to its help documentation.
 If users do not specify the requested item's data type, it will be set to the default setting by the application. For
more information on the specific driver's supported data types, refer to its help documentation. The default data
type will be displayed in bold letters.
Note: In this example, the Simulator driver is to explain addressing. Assume that the channel name is 'Channel1' and
the device name is 'Device1'.
In a Non-OPC Client
In order to get data from register 'K0001' in the simulated device, use an Item ID of 'Channel1.Device1.K001.' The
default data type for this register is 'Short.' Since non OPC Clients do not provide an update rate to the server, the
dynamic tags default update rate will be 100 msec. Both data type and update rate can be overridden after the dynamic
request is sent.
To override the tag defaults, use the commercial AT sign (@) at the end of the item. If intending to add the register as
a DWord (unsigned 32 bit) data type, simply use an Item ID of 'Channel1.Device1.K0001@DWord.' To change the
default update rate to 1000msec , use 'Channel1.Device1.K0001@1000.' To change both defaults, use 'Channel1.
Device1.K0001@DWord,1000.'
Note: The client application must be able to accept special characters like the '@' in its address space.
In an OPC Client
In an OPC client, the same syntax can be used to override the data type if the client application does not provide a
means of specifying a data type when adding the OPC Item. Since the item's update rate is not used in OPC, there is no
need to override it.
Note: The client application must be able to accept special characters like the '@' in its address space.
How To... Process Array Data
Many of the drivers available for this server allow clients to access data in an array format. Arrays allow the client
application to request a specific set of contiguous data in one request. Arrays are one specific data type; thus, users
would not have an array with a combination of Word and DWord data types. Furthermore, arrays are written to in one
transaction. To use arrays in the server, the client application must support the ability to at least read array data.
In a DDE Client
Array data is only available to the client when using CF_TEXT or Advanced DDE clipboard formats.
For client applications using Advanced DDE, the number of elements in the array is specified in the
sPACKDDE_DATAHDR_TAG structure. Only single dimensional arrays are supported by this protocol. This structure
should be used when poking array data to the server.
For clients using CF_TEXT, one or two-dimensional arrays are supported. Data in each row is separated by a TAB
(0x09) character and each row is terminated with a CR (0x0d) and a LF (0x0a) character. When a client wants to poke