NetDDE setting

The NetDDE is an extension of the DDE communication standard for the network communication. In the OS Windows 2000 and higher it is the Service and it is advisable to set the service as "run automatically".
Caution. From certain reasons it is necessary to have installed the network protocol Netbios or NetBEUI for the NetDDE functionality. In the OS Windows it is possible to install the stand-alone NetBEUI protocol or to have Netbios services switched on in the TCP/IP protocol. But these protocols are not routeable - it means that by the NetDDE communication it is possible to transfer data only in one local network. In large company networks that consist from more servers it is impossible to communicate by the NetDDE! This is also the reason why it is better to use prefarably other types of communications, for example XML data sharing.
Setting NetDDE server side:

If we want to provide the "PROMOTIC" service, "OBJECT" topic, "item1" item and all this from the computer with the "USER" name, then execute the following steps:

- Start the NetDDE (for the description see above).
- Start the DDEshare.exe program, which is the DDE manager. By this, the selection of the DDE data offer is made on the computer where the DDEshare.exe was started.

In the Share menu in the DDE Shares item a new share is added after pressing the Add and Share buttons. It is necessary to enter:

- Share name: the name terminated by the '$' char, for example MYSHARE$
- Application name: for example PROMOTIC
- Topic name: for example OBJECT
- Acces type: FULL (read and write) or READONLY
- Grant acces to all items

Confirm the window by pressing the OK button. Press the Trust share button and a window appears where options are checked for the share

- Start Application Enable
- Initiate to Application Enable

Confirm all by the OK button and close the program. The OS Windows stores these data into its database that is preserved even after the restart of the computer.

Setting NetDDE client side:

Start the NetDDE (for the description see above). The remote client refers to the service by:

- service: '\\USER\NDDE$'
- topic: 'MYSHARE$'
- item: item name of the "PROMOTIC" service, of the "OBJECT" topic that the computer with the network name "USER" offers by the above mentioned way by the NetDDE, in this case for example "item1".
Example in the Excel format
PROMOTIC 8.3.21 SCADA system documentation - MICROSYS, spol. s r.o.

Send page remarkContact responsible person
© MICROSYS, spol. s r. o.Tavičská 845/21 703 00 Ostrava-Vítkovice