Configure 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 automatically.

(We also offer a toolkit to develop new communication drivers. For more information, contact your software distributor.)

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:

• On the Insert tab of the ribbon, in the Communication group, select Add/Remove Driver; or

• Right-click the Drivers folder in the Project Explorer, and then select Add/Remove drivers on the shortcut menu.

Both methods open a Communication Drivers dialog, which displays a list of available drivers.

Use the parameters on this dialog, as follows:

• Available Drivers: Lists all available drivers and a brief description of each.

• Help: Select to open the Help menu, which contains detailed configuration instructions for the driver currently highlighted in the Available Drivers field.

• Select: Select the driver currently highlighted in the Available Drivers field.

• Selected Drivers: Lists all selected drivers and their descriptions (if available).

• Remove: Click to remove a driver currently highlighted in the Selected Drivers field.

  Note: If you remove a driver from a project, any settings that were configured for the driver will remain. If the driver is later added back to the project, these settings will be present; it cannot be assumed that the default settings will be in place. Likewise, any certificates used for secure communication (such as for the MQTT driver) will remain in the appropriate certificate stores unless removed through other means.

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.

Use the parameters on this dialog, as follows:

• Serial Encapsulation field: Enables serial drivers to communicate with modem, TCP/IP or UDP connections. This setting is supported only for serial drivers developed with the UNICOMM library, which includes most of the serial drivers available in the product.

  Note: IoT View does not support Serial Encapsulation.

  Note: This section covers only the None option, which enables the driver to connect using a normal serial channel. Please refer to "Using TCP/IP and UDP Encapsulation" and "Using Modem Connections" below for more information about other encapsulation modes. "Serial Encapsulation Tests" below lists the drivers that have been tested with modem, TCP/IP and UDP modes.

• COM, Baud Rate, Data Bits, Stop Bits, and Parity fields: Configure the parameters for the serial port connection.

  Setting	Default Value	Valid Values	Description
  COM	COM1 or COM2	Varies, up to COM256	Serial port of the PC used to communicate with the device
  Baud Rate	9600	110 to 115200	Communication data rate (bits per second)
  Data Bits	8	5 to 8	Number of data bits used in the protocol. (ASCII is typically 7 bits; RTU is typically 8 bits.)
  Stop Bits	1	1 or 2	Number of stop (synchronization) bits used in the protocol.
  Parity	None	Even, Odd, None, Space, or Mark	Parity of the protocol.

• Long1, Long2, String1, and String2 fields: These fields are driver custom settings. See the appropriate driver manual for more information.

• Buttons: Possible buttons at the bottom of this dialog include Advanced button, Authentication button, Store & Forward button, and Certificates button. The Advanced button appears in this dialog for every driver (even if inactive) and the Authentication button appears for several drivers, so they are explained below. The other buttons and driver-specific settings accessed using the Advanced and Authentication buttons are explained in the individual driver manuals as applicable.

• Advanced button: Select to open the Advanced settings dialog. Use this dialog to change the default driver parameters.

  

  These parameters are not available for all drivers; see the driver manuals for more information. The defaults for most drivers are shown in the image above. You can specify or change the default driver parameters as follows:

  • Timeout (ms) area:

    • Start message field: Specify the timeout for the message start.

    • End message field: Specify the timeout for the message end.

    • Interval between char field: Specify the timeout between each character.

    • Wait CTS field: Specify the timeout for the Clear to Send wait.

  • Handshake area:

    • Control RTS drop-down list: Specify whether to use the RTS (Request to Send) handshake. This setting is dependent on the hardware configuration, for example using a Data Communication Equipment (DCE) converter (such as 232/485) to connect to the target device. Check the specific driver manual or the device manual for the appropriate setting. The options are:

    • no (default): Do not set the RTS handshake signal before communication.

    • yes: Set the RTS handshake signal before communication.

    • yes+echo: Set the RTS handshake signal before communication, and echo the signal received from the target device.

    • Always on: The RTS handshake signal is always set.

      Note: If the Control RTS setting is configured incorrectly, the runtime communication will fail and the driver will generate a –15 status (error) code. See Read/write status codes for direct communication drivers for more information.

    • Verify CTS drop-down list: Specify whether to use the CTS (Clear to Send) type of verification. The options are no (default) or yes. Check the specific driver manual or the device manual for the appropriate setting.

  • Disable DTR checkbox: Click (enable) this box to disable the DTR function (the driver will not set the DTR signal before starting the communication).

  • Protocol area:

    • Station field: Some unit drivers such as the Modbus Server (MODSL) require a unit network address. Use this field to specify the unit address.

    • Retries field: Type a numeric value to specify how many times the driver will attempt to execute the same communication command before considering a communication error for this command.

  • Buffers length (bytes) area:

    • Tx Buffer field: Specify the transmission buffer length (in bytes).

    • Rx Buffer field: Specify the reception buffer length (in bytes).

  • Simultaneous Requests area (available only on selected drivers). The maximum number of simultaneous requests depends on the device and protocol specifications. Check the specific driver manual or the device manual for the appropriate setting.

    • Maximum field: Specify the maximum number of requests that may be sent simultaneously to all connected devices.

    • Maximum per station field: Specify the maximum number of requests that may be sent simultaneously to a single device.

• Authentication button: This button is only available for some drivers, and does not appear unless the driver uses it. Select the button to open the Authentication dialog. Use this dialog to enter authentication information (Username and Password) for each Station used in the Main Driver Sheet and Standard Driver Sheets (see below for more information). Right-click in a row to Insert line or Delete line. Select the OK button to save the information and close the dialog. See driver manuals for more specific information.

  

  Note: Some drivers use authentication that is incompatible with increasing either of the Simultaneous Requests field values. If using authentication with these drivers, do not change these values from the default of 1. These drivers are COSYS, MACHA, MQTT, SITIA, SNMP, and SOMAC. See the driver manuals for more information.

The development application provides two interfaces, which you can use to configure the driver (associating project tags to device addresses):

• Main Driver Sheet: Provides the easiest method for configuring communication between project tags and device addresses. This interface allows you to automatically group tags to provide the best performance during runtime. You cannot use this interface to control the time needed to scan a group of tags individually.

• Standard Driver Sheets: Allows you to control the time needed to scan a group of tags individually.

You can use both sheets at the same time.

Use 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:

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 String expressions.

   • 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:

You can enable the modem connection by following the steps below:

3. Right-click on the driver's folder, and then choose Settings from the shortcut menu.

   This will give you access to the communication parameters.

4. In the Serial Encapsulation menu, select Modem:

   

   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 String expressions.

   • 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.

     Note: 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.

     

   • 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. 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. TI500 has been fully tested for the encapsulation modes. Please contact customer support or your software distributor for other drivers.