I am brand new to AdvancedHMI and MODBUS but have connected successfully to a Mitsubishi FX3G PLC c/w a FX3U-ENET module using the ModbusTCPCom driver. (As an aside, I have also connected a Mitsubishi FX3G c/w a FX3U-232ADP-MB Serial module using the ModbusRTUCom driver.)
An observation using VS2012 Express with AdvancedHMI 399m and Modbus/TCP is as follows....
When polling COILS using address 00001 to 00003 for example, only devices 00001 and 00002 return status values when the form is running, by adding additional COIL addresses, then the returned TRUE or FALSE status signals always seem to stop one short. The COILs being read are M0 thru M4 in the PLC shown.
To double check this I added a button with code behind to independently check the coils, and all coils required reported correctly. (See the first attached image.) Also, here is the code behind...
Private Sub btnReadCoils_Click(sender As Object, e As EventArgs) Handles btnReadCoils.Click
Dim CurrentValues() As String = ModbusTCPCom1.Read(CStr(TextBox1.Text), 8)
Dim msg As String = ""
For i = 0 To CurrentValues.Length - 1
msg = msg & "Index " & i + 1 & "=" & CurrentValues(i).ToUpper & vbNewLine
Next
MsgBox(msg)
End Sub
If we disconnect the actual Ethernet cable to the PLC, we then get the error message display that indicates that only the first 4 devices are actually being polled, which chimes with the experience described above. (See second attached image.)
