B&B Electronics MODSCAN32 - Manual - Manual (Page 63)

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MNetSvr Overview
The MNetSvr application was designed to operate as a MBAP compatible interface between network client
applications, (such as ModScan32), and serial slave devices. MNetSvr opens TCP Port #502 and listens for
other network devices to initiate a connection. When a connection is made, MNetSvr spins off a separate
thread of execution to process requests from the connected client. As far as the client application is
concerned, it appears as though it has exclusive access to the slave device, with all messaging activity
identical to that which would occur if the device were connected locally.
MNetSvr supports modbus message types 01-06, 15& 16. Requests for modbus data are accepted via a
network connection, forwarded to the specified serial slave device, and the response from the slave is
transmitted back to the network client.
Commands
There is only one menu command supported by the MNetSvr application. File Connect allows you to
define the operating characteristics of the PC COM port used for communication with the serial slave
device(s). This command provides a dialog box to define the associated baud rate, parity, and protocal,
(ASCII or RTU), which matches the characteristics of the attached slaves. The serial connection must be
started prior to data being made accessible to network devices.
Views
The MNetSvr display window is divided into two parts, (views), separated by a horizontal splitter control.
The splitter bar is used to adjust the relative sizes of the two views.
The upper splitter view is used to display network events. As client applications connect and disconnect, a
message will be added to the display which details the time and description of the event.
The lower splitter view is used to display the serial data stream as transmitted to and from a connected slave
device. Each modbus transaction occurring between the MNetSvr application and a slave device will be
displayed in this view.