Configuring direct communication with a remote device

A communication driver is a DLL containing specific information about the remote equipment and implements the communication protocol. Drivers for dozens of common and not-so-common devices are installed with InduSoft Web Studio.

( InduSoft also provides a toolkit to develop new communication drivers. For more information, please contact Customer Support.)

The Drivers task/worksheet allows you to define the communication interface (or interfaces) between the project and remote equipment; such as a PLC, a single-loop, and transmitters.

Note: Consult the Help menu for a description of the functions and characteristics that are standard for all drivers. When developing a project, you can also refer to the specific documentation provided with each communication driver. This documentation is usually located in the DRV directory.

To configure a communication driver, you must specify the interface parameters (for example, the station address and the baud rate), specify the equipment addresses, and then link them to project tags.

Use one of the following methods to add or remove a driver:
Both methods open a Communication Drivers dialog, which displays a list of available drivers.
Figure 1. Communication Drivers dialog

Use the parameters on this dialog, as follows:

When you click OK in the Communications Driver dialog, you create a subfolder for the selected driver(s) in the Drivers folder located on the Comm tab.

You can right-click on a driver subfolder to access the Settings option, which opens the Communications Parameters dialog.
Figure 2. Sample Communications Parameters dialog

Use the parameters on this dialog, as follows:
Figure 3. Advanced Settings dialog

Specify or change the default driver parameters as follows:
The development application provides two interfaces, which you can use to configure the driver (associating project tags to device addresses):

You can use both sheets at the same time.

Using TCP/IP and UDP Encapsulation

Most of the serial drivers allow the use of TCP/IP or UDP/IP encapsulation. The encapsulation mode has been designed to provide communication with serial devices connected to terminal servers on your ethernet or wireless networks. A terminal server can be seen as a virtual serial port. It converts TCP/IP or UDP/IP messages on your Ethernet or Wireless network to serial data. Once the message has been converted to a serial form, you can connect standard devices that support serial communications to the terminal server. The following diagram provides one example of applying this solution:
Figure 4. TCP/IP Encapsulation

You can enable the encapsulation by following the steps below:
  1. Right-click on the driver's folder, and then choose Settings from the shortcut menu.

    This will give you access to the communication parameters.

  2. In the Serial Encapsulation field, select TCP/IP or UDP/IP:


The following fields are available:
  • IP Address field: Specify the IP Address for the Terminal Server. This field accepts tags in curly brackets.
  • Port Number field: Enter the TCP/IP or UDP/IP port number.
  • Status Tag field: This field is available only when using TCP/IP. The tag on this field receives the value 1 when the TCP/IP connection is established; otherwise, it receives 0.
  • Server Mode field: The TCP/IP encapsulation allows the Server Mode, making the remote client responsible for establishing the connection to enable the communication.

Using Modem Connections

Most of the serial drivers allow the use of modem connections. The modem connection has been designed to enable communications with remote serial devices connected through a phone line. The following diagram provides one example of applying this solution:
Figure 5. Modem Connection

You can enable the modem connection by following the steps below:
  1. Right-click on the driver's folder, and then choose Settings from the shortcut menu.

    This will give you access to the communication parameters.

  2. In the Serial Encapsulation menu, select Modem:


CAUTION:
The Modem option is not supported for Pocket PC v3.00 or older.
The following fields are available:
  • Name drop-down list: Select the modem that the driver will use to establish the connection. If you do not know the modem name, use the Auto Detect option. The Auto Detect 1 will use the first modem available, Auto Detect 2 will use the second, Auto Detect 3 will use the third, and Auto Detect 4 will use the fourth.
  • Phone field: Enter a phone number that the driver will use to connect to the remote device. This field accepts tags between curly brackets.
  • Settings button: Click on this button to configure the modem settings. The window that displays when you click on this button depends on the operating system that you are using and on the modem type.
    CAUTION:
    The settings configured by clicking on this button are not saved with your project. The information is saved on the operating system registry, and they are valid only in the computer that you are interacting with. If you install your project on another computer, you will have to reconfigure these settings.
  • Connection button: Click to open the Connection Control window. The default connection settings should suffice for most of the projects. However, you can take full control over the connection, and also enable incoming calls, by clicking on this button.
    Figure 6. Connection Control dialog

    • Dial out trigger field: When the value of the tag configured in this field changes, the driver will try to connect to the remote device. If the connection has already been established, the command is ignored. You do not have to use this field if you are using Auto Connect.
    • Hang up trigger field: When the value of the tag configured in this field changes, the driver will disconnect from the remote device. If the device is disconnected the command is ignored. You do not have to use this field if you are using Disconnect call if idle for more than.
    • Auto Connect field: When this option is enabled, the driver will try to connect to the remote device before sending any information. If the connection fails, the next attempt will be made after the Retry Interval has expired.
    • Disconnect call if idle for more than field: When this option is checked, the driver will automatically disconnect from the remote device if no communication is performed after the time you specified.
    • Enable incoming calls field: Check this option if you want to enable the driver to receive calls from the remote device. You can use the Hang up trigger to drop the call once it has been established. Notice that one driver can use both incoming calls and outgoing calls.
  • Status area
    • Code field: Enter with a tag that will receive one of the following codes when the driver is running:
      • 0 = Disconnected
      • 1 = Connected
      • 2 = Dialing
      • 3 = Dropping
      • 4 = Closing Line
    • Description field: Enter with a tag that will receive a complete description of the current status. The description is associated with the Code field; however, it brings some additional information about the current status.

Serial Encapsulation Tests

Most of the serial drivers should work with every serial encapsulation mode. However, most of the drivers were developed before the encapsulation modes had been created. The following table lists the drivers fully tested with certain encapsulation modes; if the driver that you intend to use is not listed and you are unsure whether it will work, please contact your distributor.

Driver Modem TCP/IP UDP/IP
MODSL X X X
ABKE X X X
MODBU X   X
OMETH X    

X = Item has been tested