Energy Meter Manual

<Toc> <Ind> < 6. Modbus/TCP Communication Protocol>
6-13
IM 77C01E01-10E
Example of the Program Created Using Visual-BASIC Version 6.0
In this sample program, command sending and response receiving are carried out by the
method for connection and sending and SendData method of Winsock control.
● Preparation
Since this sample program uses Winsock control, it is necessary to assign the
Microsoft Winsock Control component. Refer to the user’s manual of Visual-Basic for
how to assign the component.
● Sample Program
Normal status check, error processing and retry processing are omitted for this proce-
dure.
The program does not operate by the procedure described in this section only. Please
make it reference at the time of actual application creation.
‘Variable declaration
‘
Option Explicit
Dim strSendData As String ‘Sending data
Dim strReceive As String ‘Received data
Dim binChrs(11) As Byte ‘Binary data
Dim iFlag As Integer ‘Flag of wait for completion
‘
‘=====================================================================
Private Sub cmdSend1()
‘Procedure to connect with PR300 by TCP/IP and to create/send data.
‘
‘Variable declaration
Dim iCount As Integer
Dim strCher As String
‘
‘Set properties of Winsock control
Winsock1.Protocol = sckTCPProtocol ‘TCP protocol
Winsock1.RemoteHost = “192.168.1.1”‘IP address of PR300 to be connected
Winsock1.RemotePort = 502 ‘Port of Modbus/TCP to be used
‘
‘Request TCP connection of PR300
Winsock1.Connect ‘Request TCP connection
Do Until Winsock1.State = sckConnected ‘Wait for the completion of connection
iFlag = DoEvents()
Loop
‘