Establishing Communication

Immediately after startup, HomSoft tries to establish communication between the PC and the Homer. Note that microwave power is not required for establishing this communication. If all goes well, you may not notice anything (perhaps a few flashing announcements). In case of problems, a dialog window will appear in order to assist in making the connection.

Other indications of failed communication are warnings like “Homer Memory Read Fail” or meaningless System Info data.

After the connection is established, HomSoft reads all required information from the Homer and verifies correspondence between HomSoft version and Server version. If a mismatch is found, a dialog box appears, informing you and offering a Server upgrade.

Case of RS232

If connection via RS232 or RS422 could not be established automatically at HomSoft start, an error message like that in Fig. 11 may pop up.

Fig. 11.  A possible error message at program startup due to failed communication.

If clicking  Retry  or  Try longer wait  buttons does not help, click the  COM Setup  button. This opens the dialog window titled COM Port Setting (Fig. 12), displaying error message COMMUNICATION FAIL, sometimes with a more detailed error description. A typical problem is incorrect COM port settings. Proceed as follows:

  • Select the appropriate device from the Ports list of the available devices. The list can be updated by clicking the  Refresh  button.

  • Select the approppriate Baud Rate, in most cases 115200 kbits/s.

  • Click  Connect .

If the connection is established, a green message CONNECTION ESTABLISHED appears and you can continue by clicking the  Return  button. Otherwise, HomSoft will terminate.

Fig. 12.  COM Port Setting dialog.

Fixed COM port settings, that cannot be modified, are: 8 data bits, 1 stop bit, no parity.

Here are some causes of failed communication and possible remedies:

  • Incorrect COM port or baudrate.

  • Homer internal Server is not running (e.g., the Homer is not switched ON).

  • Homer internal Server is running in CAN Bus mode, or the Download Server is running. Listen for Morse signal at Homer power-up, or use a COM port monitor as instructed in Choosing Homer Power-up Server.

  • Problem is in interconnection:

  • Verify whether the connecting RS232 cable is null modem (crossed TX-RX wires).

  • Verify whether the connecting cable is firmly in its position and click the  Connect  button.

  • Verify the integrity of the cable. Fix or replace the cable and click the  Connect  button.

  • Problem is at the PC end:

  • COM port settings in HomSoft do not agree with those of theHomer unit. In this case, you should set the proper port number and baudrate and click the  Connect  button. Homer baudrate is normally fixed to 115200 kbits/s. (HomSoft is able to find the correct baudrate by clicking the  AutoFind  button.)

  • One source of problem in older PCs may be that some SW installed in your PC tries to use the same COM port as HomSoft, at least from time to time. It may be a PCMCIA card (e.g., a modem). Try the following:

  • Use another COM port if available.

  • Uninstall PCMCIA cards and observe the effect.

  • Provide your PC with COM port extension card (PCMCIA-to-RS232 adapter) and use another COM port (HomSoft supports COM1 to COM99).

  • A usual solution is to use a USB-to-RS232 adapter connected to an USB port in your PC. The COM Port Setting window shows which of the available ports correspond to that adapter.

  • Problem is at the Homer end:

  • Verify that the Homer DC power supply is on.

  • Terminate HomSoft. Switch the Homer DC power supply OFF. Wait for about 10 seconds. Switch the Homer ON again and watch for Morse code to be sure that the Server is running with the correct communication interface.

  • Restart HomSoft.

  • The Homer is busy: If, after power-up, the Homer is instructed by its internal Hom.cfg and Tun.cfg configuration files to start measurement or even tuning automatically, it may respond to commands from your PC with delay. In this case, increase Timeout in COM Port Setting dialog window (edit or choose from the drop-down list) and click the  Connect  button.

Once the connection is established, the green message CONNECTION ESTABLISHED appears and you can continue by clicking the  Continue  button.

The COM Port Setting dialog can be invoked anytime by clicking the Commun|COM Port menu item.

A Note on USB-RS232 Adapter

Problems with communication (e.g., when transferring all samples in Rectified and Pulsed modes of sampling) or even PC crash may be experienced with certain brands of USB-RS232 adapters (some contain a fake chip instead of a genuine one). If such problems occur, try another brand of the adapter.

Case of CAN

One possible problem at HomSoft start is an incorrectly installed or unrecognized CAN Bus adapter. Then, an error message like that in Fig. 13 may pop up. Clicking  Yes  attempts to use a different adapter type. Sometimes, simply disconnecting and reconnecting of the USB adapter plug, and then clicking  Retry  resolves the issue. If the problem persists, please read the accompanying CanBusCommProblems.pdf document.

Fig. 13.  CAN Bus adapter error.

If the adapter has been recognized but the connection with the Homer still fails, a dialog window titled CAN Bus Setting shows up (Fig. 14), displaying the error message COMMUNICATION FAIL. The cause may be that the Homer is busy with lengthy measurement and responds with a delay longer than the set timeout (in this case, repeatedly clicking the  Connect  button may help), or there is CAN baudrate discrepancy. This dialog window enables the user to either set CAN baudrate on the PC side manually or detect it automatically. Be sure the CAN cable is properly connected and terminated with a 120-ohm resistor at both end devices (see Electrical Connection – CAN Bus).

Fig. 14.  CAN Bus Setting dialog.

To establish communication manually:

  • From theHardware drop-down list (Fig. 14), select the CAN Bus interface your PC is equipped with.

  • Set Baudrate (you can also try a different Timeout).

  • Click  Connect  and wait for a message.

  • If the message is CONNECTION ESTABLISHED, reset Timeout to the original value and click the  Continue  button. If the message is COMMUNICATION FAIL, repeat clicking  Connect  several times, then try another baudrate.

  • If the communication fails repeatedly, try disconnecting the CAN Bus cable from the installation (from the Homer device or at the position designated “X” in Fig. 6) but leave your CAN Bus Adapter connected to the USB port of the PC (or, better yet, pull it out and plug it back in). Then start again with the Hardware drop-down list, even if the proper adapter is shown. (The reason is that the CAN Bus adapter should be configured properly prior to connecting it physically to a CAN Bus network, otherwise it may impair the running traffic.)

To establish communication automatically:

  • From the Hardware drop-down list, select the CAN Bus interface your PC is equipped with.

  • Click  AutoFind  and wait (abort by  Stop ).

  • Read the message. If the message is CONNECTION ESTABLISHED, reset Timeout to the original value and click the  Continue  button. If the COMMUNICATION FAIL message persists, proceed as follows:

  • Verify the interconnecting cable integrity.

  • Verify that the Homer DC power supply is on.

  • Terminate HomSoft. Switch the Homer DC power supply OFF. Wait for about 10 seconds. Switch the Homer ON again and watch for the Morse code to confirm that the Server is running with the correct communication interface.

  • Restart HomSoft and retry establishing communication.

The CAN Bus Setting dialog can be invoked anytime by clicking the Commun|CAN Bus menu item.

If communication problems arise while measuring, please refer to Problems with Communication topic.

Problems with Communication

At HomSoft Start

See Establishing Communication if you encounter problems with communication at HomSoft start.

During Measurement

If, while measuring, the communication is interrupted (e. g. the RS232 or CAN Bus cable is unplugged), the data monitoring is suspended (the displays appear frozen) and the following message appears in the left panel of the HomSoft bottom Status Bar: COM Timeout.

After the communication has been re-established, the measurement will resume.

Sometimes, problems may occur in Rectified or Pulsed modes of sampling, especially in the case of CAN, because the system cannot “listen” while sampling and processing the samples. As a result, the commands may fail on timeout. You are usually informed of it and prompted to retry the command.

In case of problems, try to stop Homer internal measurement (Homer|Stop Homer menu item or the equivalent toolbar button) and wait for the expected timeout (until the top-left Run-Pause button returns to the Off state and its icon changes from to ). Then re-issue the failed command.

After the measurement start (after clicking ), the current timeout (the time HomSoft will wait for a response to commands), is displayed in the right-most panel of the HomSoft bottom Status Bar.