UM0239 datasheet(37/44 Pages) STMICROELECTRONICS

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UM0239

Communication session examples

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Note:

After selecting COM port, the Status Bar is updated showing information about the selected

COM port, SW/FW revisions and the Link status.

Before starting a Communication session, the user must perform a Write Control Register

for the two windows.

Click REG on the toolbar to open the Control Register dialog box.

Ensure that the Dual Channel feature is disabled.

Because only few bits change for the sessions in respect to the default Control Register

parameters, click Read CTRL Register and then Update CTRL Panel.

Set the Carrier Frequency to 72 kHz and the Detection Method to Preamble to

ensure that the incoming data are received only when a preamble is detected across

the Mains.

Now, the two Control Register dialog boxes should appear as shown in Figure 22.

Figure 22.

Control Register dialog boxes after setup

Once the Control Registers are correctly configured, communication can begin between the

boards.

8.2

Communication session without Frame Synchronization

In this example, the board connected to COM1 is used as the Transmitter while the board

connected to COM3 is used as the Receiver. Five messages are transmitted across the

Mains and the receiving method is not synchronized, so incoming data from ST7540 are

sent directly to the PC.

Actions to perform on GUI connected with COM3:

Click Rx on toolbar to open the Rx Monitor dialog box.

Set FRAME SYNC to OFF.

Click ON.

Now the receiving board is waiting incoming data. (It activates itself only when a preamble is

detected across the Mains).

Actions to perform on GUI connected with COM1:

Click Tx on toolbar to open the Tx Monitor dialog box.

Write the preamble "AAAAAAAA" in the hexadecimal textbox.

COM 1

COM 3

UM0239 데이터시트(PDF) 37 Page - STMicroelectronics