Transferring Logged Data from the FP-20xx through Serial Modem Communication

You can use the FP Send File Via Modem VI and FP Receive File Via Modem VI to transfer files between the FP-20xx and a computer or between two FP-20xx modules. These VIs use standard AT commands to dial, disconnect, and set the modem to auto answer. When transferring files, the data is sent in 100 byte chunks with a CRC-16 error checking to make sure the data arrives uncorrupted. Although transferring data through a modem is a valid and easy method of transferring data, it is a relatively slow method. You can use the Modem.llb to communicate with a modem using the serial port. Send standard Hayes-compatible AT commands to the modem to dial a number, send data, hang up, and so on.



To transfer files using the FP Send File Via Modem VI and FP Receive File Via Modem VI, follow these steps:

1. Place the FP Send File Via Modem VI on the FP-20xx.

2. Select the baud rate from the BaudRate menu. When you run the VIs, if the connection times out or the modems disconnect, select a lower baud rate. Older modems may not be able to transmit to the computer at the speed you initially selected or the line may have noise that causes the modems to disconnect. Lowering the baud rate produces a more stable connection that is less affected by noise.



3. Select the correct COM port from the COM Port menu.

4. Enter the file you want to send in the File to Send field.

5. Run the FP Send File Via Modem VI.

6. Click Turn on Auto Answer. The FP-20xx waits to be called. When it is called, it connects, sends the file, and disconnects.

7. Place the FP Receive File Via Modem VI on the computer calling the modem.

8. Select the same BaudRate that you selected for the FP Send File Via Modem VI.



9. Select the correct COM port from the COM Port menu.

10. Enter the Phone Number.

11. Enter the file to which you want the data saved in the Receive File Path.

12. Run the FP Receive File Via Modem VI.

13. Click Dial Modem. The VI dials the FP-20xx, downloads the file, and disconnects.

Customizing the Modem VIs
If you are incorporating the modem VIs in a datalogging application, program the modem VIs on the FP-20xx to run in a parallel loop. Run the Check for Incoming Call VI every second to detect an incoming call. When the VI detects an incoming call, the VI sends the data, disconnects, and restarts. This method of programming prevents the FP-20xx processor from being taxed while it is waiting for an incoming call.

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