modbus scan

1. ModScan Overview 1.1 Document/View Architecture 1.2 Modbus Data Definition 1.3 Display Formats 1.4 Connecting to a Modbus Network 1.4.1 Direct Serial Connections 1.4.2 Modem Connections 1.4.3 Network Connections 2. Menu Commands 2.1 File menu 2.2 Connection menu 2.3 Setup menu 2.4 View menu 2.5 Window menu 2.6 Help menu 3. Tool & Status Bars 3.1 Toolbar 3.2 Format Selections 3.3 Status Bar 4. Testing Features 4.1 Writing Data to the Modbus 4.2 Message Counters 4.3 Observing Serial Traffic 4.4 Capturing Data to Text File 4.5 User Defined Commands 4.6 Scripts 5. Using ModScan with a Database 6. Using OLE Automation 6.1 Overview 6.2 Automation Routines 7. Distribution/Registration 7.1 Pricing 7.2 Licensing 7.3 Support 7.4 Other Products 1. ModScan Overview The ModScan application operates as a MODBUS mastermodbus_protocol device in either RTU or ASCII transmission modes. ModScan may be used to access and modify data points contained in one or more MODBUS slave devices connected to the PC via a serial port, modem, or network. ModScan supports the standard MODBUS message types 01-06, 15 & 16, as well as providing the ability for you to exercise special features of a slave device by transmitting custom command strings and observing the response. ModScan is a useful test and diagnostic tool for verifying the proper slave response to MODBUS queries as well as being a low cost data collection tool for interfacing data into PC database and spreadsheet applications. 1.1 Document/View Architecture ModScan utilizes the standard Windows Multiple-Document-Interface, (MDI), architecture for displaying modbus data to the user. Each document represents a series, (array), of modbus data points identified by the following parameters: Slave Device Address Represents the physical device attached to the modbus network Data Type Internal data representation, (i.e. input, coil, register) Data Address Point address within the device Length Number of points to scan/display Associated with each document is also a timer, which is used to periodically scan new data from the defined slave and refresh the display. The modbus data definition is accessible from the ModScan menu or via edit controls in the top splitter window of the document display. As new data is obtained from the slave device, it is written to the bottom splitter window in one of several formats, depending upon your preference. The size of each document display window is adjustable via the splitter control. 1.2 Modbus Data Definition The upper half of each Document's View represents the data selected for display, (and possible capture to a historical data file). In most testing applications, the ModScan will only be connected to a single modbus slave device, however, in a multidrop modbus network, there may be several devices accessible from a single connection. The "Device Id" edit control allows you to specify the slave address for the source of the data. Likewise, edit controls are available to select the point type, data address, and number of data points to access. Notice that the modbus protocol uses a 5-digit representation for the slave data address which infers the point-type. For example, INPUT STATUS values are always represented in the range 10001-19999: HOLDING REGISTERS are displayed as 40000-49999. The ModScan application uses the standard notation for displaying data in the bottom splitter window, however the address specified in the upper splitter address edit control assumes a 4-digit physical point address. This address, coupled with the point-type specifier completely defines the data to be accessed in the slave device. The upper splitter window also contains two counters which are used to tally the number of data requests made from this document to the modbus connection and the number of valid slave responses received in reply. A button is available within the display which resets the counters associated with this document. 1.3 Display Formats As data is received from the slave device, it is displayed to the lower splitter view of the associated document. Any errors incurred during the exchange of information will be displayed on the first line. The font and colors used to display the data is configurable via the View, Config menu options. Modbus register data may be displayed in any of the following formats: Binary Data displayed as 16 discrete values. Decimal Ranges from -32767 to 32768 Hexadecimal 0000-ffff Floating Point IEEE Standard Floating Point Notation (Requires two registers per value) Word-Swapped Floating Point Inverted Floating Point used by some processors Double-Precision Floating Point 64-bit Floating Point Notation Word Swapped Dbl Precision Inverted 64-bit Float Values 1.4 Connecting to a Modbus Network 1.4.1 Direct Serial Connections ModScan may be used to obtain data from modbus slave device connected to the PC in one of three basic physical arrangements. The most common connection is via any one of the four available PC serial COM ports. ModScan uses the standard Win32 software drivers for communication with the COM ports, thereby providing support for any hardware serial boards which may be installed in the Windows operating system, (including RS-232, RS-485, etc.). You have complete control over the operating characteristics of the serial connection by selecting the appropriate baud rate, parity, and control line, (handshaking), properties to match the slave device(s). 1.4.2 Modem Connections In remote testing situations, the ModScan application may be used to communicate with a modbus network over a dedicated modem connection. ModScan supports the TAPI, (telephony application interface), standard implemented in Windows and Windows NT. If selected, the modem connection dialog allows you to enter a phone number for dialing. Any TAPI device configured within the Windows operating system is available for use. It is also possible to connect via modem to a remote system utilizing the built-in networking characteristics of Windows '95 & NT. To do this, you will need to configure the ModScan application to connect via a TCP/IP connection which has been setup within Windows to automatically dial and establish a PPP connection with another Windows machine which is connected directly to the slave device(s) you wish to use. In this case, ModScan operates as if it were using a network card connected directly to a modbus to tcp/ip bridge device. 1.4.3 Network Connections ModScan allows modbus communications to occur over a TCP/IP network. This feature requires the use of a modbus to TCP/IP bridge device which can service network requests from the network and obtain the data from a connected slave device prior to responding to queries from the ModScan application. A bridge device operates as a network server, providing support to numerous client applications distributed over the network. WinTECH Software provides such a server for interfacing to a single serial modbus network. Third-party vendors may provide various solutions for interfacing TCP/IP to modbus devices via other hardware, (i.e. modbus plus, etc.). If the interfacing specification for these network bridge devices is available in the public domain, they may be included in future releases of the ModScan application. If you have the need to use ModScan with a third-party vendor's equipment, please contact the WinTECH Software support line for consideration. 2. Menu Commands 2.1 File menu The File Menu offers the following commands: New Creates a new ModScan document. Each document represents a different block of data from a modbus device. Open Opens an existing document. Close Closes an open document. Save