905U-D Radio Modem FAQ

From dataTaker Wiki (FAQ)

905U-D Radio Modem Frequently Asked Questions
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Contents

Obsolete product notice

dataTaker no longer carry the 905U as part of the dataTaker product range.


How do I configure the 905U-D Modems?

To use the 905U-D Modems with the dataTaker data loggers, configure them for "Controlled Mode". "Controlled Mode" allows the 905U-D units to control the flow of data, providing “point-to-point” communications, similar to phone modems. This can be either Auto-Connect mode or Single-Connect mode. The modems should be configured using the 905U-D windows configuration program provided by elpro.

Auto-Connect Mode

Auto-Connect Mode is similar to "fixed line" modem operation. The master unit wants to connect to only one slave address. The modems from Datataker Pty Ltd are configured in this mode.

General Configuration

  1. Two Modems set up as “Auto-Connect Master”, and “Auto-Connect Slave” in CONTROLLED mode.
  2. Both modems need to have the SAME System Address
  3. Both modems need to have UNIQUE unit addresses

Auto-Connect Master Configuration

  1. Under the heading “Operating Mode:” and “Controlled” select “Auto-Connect Master”.
  2. Under “Controlled Mode Options”>>”General”, select your “System Address” for the modems. For our example, we will use “111”
  3. Select your unique “Unit Address”. This example, the master modem will have a unit address of “1”.
  4. Under “Controlled Mode Options”>>”Advanced”, “Link Check Time” place a value of 10 seconds. The link check time allows the master unit to transmit a check message to the slave unit, which the slave unit will acknowledge.
    For more information, consult the “Configurations Program”>>“Controlled Mode”>>“Controlled Mode Options” section of the Elpro 905U-D Users Manual.
  5. For a DT500 data logger, set the “Radio” “Data Rate” to be “19200”, and the “Serial” “Baud Rate” to be “9600”. For a DT800 data logger, set the “Radio” “Data Rate” to be “57600”, and the “Serial” “Baud Rate” to be “57600”. If possible, set the “Radio” “Data Rate” to be the same as the “Serial” “Baud Rate”. If the serial baud rate is less than the radio data rate, a single message may be broken into two messages.
    For more information, consult the “Serial/Radio Rates” section of the Elpro 905U-D Users Manual.
  6. Select “PLC Mode” and allow the configuration software to automatically adjust the S18 and S19, preventing messages been broken into multiple messages.
  7. Set the flow control for the modem under “Settings”>>”Serial”. If connecting the modem to a PC, we recommend hardware flow control (CTS/RTS).
  8. Select "Enable CRC Error Checking" under “Settings”>>”Radio” to enable error checking.
    For more information, consult the “What Operating Mode to Use?”>>"Error Check?" section of the Elpro 905U-D Users Manual.

Auto-Connect Slave Configuration

  1. Under the heading “Operating Mode:” and “Controlled” select “Auto-Connect Slave”.
  2. Under “Controlled Mode Options”>>”General”, select your “System Address” for the modems. For our example, we will use “111”
  3. Select your unique “Unit Address”. This example, the slave modem will have a unit address of “2”.
  4. Under “Controlled Mode Options”>>”Advanced”, “Inactivity Timeout” place a value of 15 seconds. The inactivity timeout allows the slave unit to reset the link if there have been no data transmissions within this time. The slave unit should see the check message sent message sent by the master unit at the link check time value.
    For more information, consult the “Configurations Program”>>“Controlled Mode”>>“Controlled Mode Options” section of the Elpro 905U-D Users Manual.
  5. If possible, set the “Radio” “Data Rate” to be the same as the “Serial” “Baud Rate”. If the serial baud rate is less than the radio data rate, a single message may be broken into two messages. This can be done with the DT80 and DT800 data loggers, which can be set to a baud rate of 57600. However the DT500 family of data loggers need to be set to a baud rate of 9600, while the minimum radio data rate is 19200.
    For more information, consult the “Serial/Radio Rates” section of the Elpro 905U-D Users Manual.
  6. Select “PLC Mode” and allow the configuration software to automatically adjust the S18 and S19 preventing messages been broken into multiple messages.
  7. Set the flow control for the modem under “Settings”>>”Serial”. If connecting the modem to a PC, we recommend hardware flow control (CTS/RTS), if connecting to a DT500 family data logger, use software flow control (XON/XOFF), if connecting to a DT80/DT800 data logger, we recommend using harware flow control (CTS/RTS).
    Note if you are connecting to a DT80/DT800 with hardware flow control, remember to configure the DT80/DT800 to hardware flow control as well, as the default for these loggers is software flow control.
  8. Select "Enable CRC Error Checking" under “Settings”>>”Radio” to enable error checking.
    For more information, consult the “What Operating Mode to Use?”>>"Error Check?" section of the Elpro 905U-D Users Manual.
  9. If connecting the slave radio modem to a dataTaker, select "Disable Local Echo" and "Disable Response Codes" under “Settings”>>”Advanced”. This prevents the radio modem sending AT commands to the logger which the dataTaker data logger does not understand.

To Set up a REPEATER in Auto-Connect Controlled Mode.

With this example, “Auto-Connect Master” will have “Unit Address” 1, “Auto-Connect Slave” will have “Unit Address” 2, and the REPEATER will have “Unit Address” of 12

  1. Select “Single-Connect” in Controlled Mode, select a unique Unit address. We will use the number 12 for this example
  2. With the “Auto-Connect Master”, under “Controlled Mode Options” select the “Stored Add” tab, then select “Dest 1” tab.
  3. The setting for “Dest Add 1” is for the “Auto-Connect Slave”, which is 2
  4. The setting for “Rpt 1” is for the REPEATER, “Single-Connect”, which is 12
  5. NOTE : You cannot use “Fast Operation” when using repeaters

Single-Connect Mode

Single-Connect Mode is similar to a dial-up modem. In this mode, the module will only make one attempt to connect to a destination address. A host device will issue a connect AT command, and the module will send a connect message to the destination address.
A common example of using this mode, is a PC polling several data loggers. The PC connects to a remote station one at a time, transfers data, disconnects and connects to the next station.

General Configuration

  1. Two Modems set up as “Single-Connect” in CONTROLLED mode.
  2. Both modems need to have the SAME System Address.
  3. Both modems need to have UNIQUE unit addresses.
  4. Both modems need the other modems UNIQUE unit address set in "Dest Add 1" for the destination address.

Single-Connect (Master) Configuration

In Single-Connect mode, there is no Master or Slave settings for the modem. We will refer to this configuration to differentiate between the Modems. The master modem will be connected to the PC.

  1. Under the heading “Operating Mode:” and “Controlled” select “Single-Connect”.
  2. Under “Controlled Mode Options”>>”General”, select your “System Address” for the modems. For our example, we will use “122”
  3. Select your unique “Unit Address”. This example, the master modem will have a unit address of “1”.
  4. Set the destination address (the slave modem, or the modem you wish to talk to) in "Dest Add 1" under “Controlled Mode Options”>>”Stored Add”.
    If connecting to multiple units place the first address in "Dest Add 1" under “Controlled Mode Options”>>”Stored Add”>>"Dest 1", the second address in "Dest Add 2" under “Controlled Mode Options”>>”Stored Add”>>"Dest 2", and so on.
  5. For a DT500 data logger, set the “Radio” “Data Rate” to be “19200”, and the “Serial” “Baud Rate” to be “9600”. For a DT800 data logger, set the “Radio” “Data Rate” to be “57600”, and the “Serial” “Baud Rate” to be “57600”. If possible, set the “Radio” “Data Rate” to be the same as the “Serial” “Baud Rate”. If the serial baud rate is less than the radio data rate, a single message may be broken into two messages.
    For more information, consult the “Serial/Radio Rates” section of the Elpro 905U-D Users Manual.
  6. Select “PLC Mode” and allow the configuration software to automatically adjust the S18 and S19, preventing messages been broken into multiple messages.
  7. Set the flow control for the modem under “Settings”>>”Serial”. If connecting the modem to a PC, we recommend hardware flow control (CTS/RTS).
  8. Select "Enable CRC Error Checking" under “Settings”>>”Radio” to enable error checking.
    For more information, consult the “What Operating Mode to Use?”>>"Error Check?" section of the Elpro 905U-D Users Manual.

Single-Connect (Slave) Configuration

In Single-Connect mode, there is no Master or Slave settings for the modem. We will refer to this configuration to differentiate between the Modems. The slave modem will be connected to the data logger.

  1. Under the heading “Operating Mode:” and “Controlled” select “Single-Connect”.
  2. Under “Controlled Mode Options”>>”General”, select your “System Address” for the modems. For our example, we will use “122”
  3. Select your unique “Unit Address”. This example, the slave modem will have a unit address of “2”.
  4. Set the destination address (the modem modem, or the modem you wish to talk to) in "Dest Add 1" under “Controlled Mode Options”>>”Stored Add”.
    If you are using multiple slave units to connect to the master modem, repeat this step.
  5. If possible, set the “Radio” “Data Rate” to be the same as the “Serial” “Baud Rate”. If the serial baud rate is less than the radio data rate, a single message may be broken into two messages. This can be done with the DT80 and DT800 data loggers, which can be set to a baud rate of 57600. However the DT500 family of data loggers need to be set to a baud rate of 9600, while the minimum radio data rate is 19200.
    For more information, consult the “Serial/Radio Rates” section of the Elpro 905U-D Users Manual.
  6. Select “PLC Mode” and allow the configuration software to automatically adjust the S18 and S19 preventing messages been broken into multiple messages.
  7. Set the flow control for the modem under “Settings”>>”Serial”. If connecting the modem to a PC, we recommend hardware flow control (CTS/RTS), if connecting to a DT500 family data logger, use software flow control (XON/XOFF), if connecting to a DT80/DT800 data logger, we recommend using harware flow control (CTS/RTS).
    Note if you are connecting to a DT80/DT800 with hardware flow control, remember to configure the DT80/DT800 to hardware flow control as well, as the default for these loggers is software flow control.
  8. Select "Enable CRC Error Checking" under “Settings”>>”Radio” to enable error checking.
    For more information, consult the “What Operating Mode to Use?”>>"Error Check?" section of the Elpro 905U-D Users Manual.
  9. If connecting the slave radio modem to a dataTaker, select "Disable Local Echo" and "Disable Response Codes" under “Settings”>>”Advanced”. This prevents the radio modem sending AT commands to the logger which the dataTaker data logger does not understand.

To Set up a REPEATER in Single-Connect Controlled Mode.

With this example, “Single-Connect (Master)” will have “Unit Address” 1, “Single-Connect (Slave)” will have “Unit Address” 2, and the REPEATER will have “Unit Address” of 12

  1. Select “Single-Connect” in Controlled Mode, select a unique Unit address. We will use the number 12 for this example
  2. With the “Single-Connect (Master)”, under “Controlled Mode Options” select the “Stored Add” tab, then select “Dest 1” tab.
  3. The setting for “Dest Add 1” is for the “Single-Connect (Slave)”, which is 2
  4. The setting for “Rpt 1” is for the REPEATER, “Single-Connect”, which is 12
  5. With the “Single-Connect (Slave)”, under “Controlled Mode Options” select the “Stored Add” tab, then select “Dest 1” tab.
  6. The setting for “Dest Add 1” is for the “Single-Connect (Master)”, which is 1
  7. The setting for “Rpt 1” is for the REPEATER, “Single-Connect”, which is 12
  8. When dialling the (Slave) modem from the PC using the (Master) modem, you will need to dial with the ATD command, or using the standard 19200 modem. The number to dial will be the REPEATER unit address, then the destination unit address.
    for this example, dialling from the master to the slave, you will use the command ATD12,2
  9. NOTE : You cannot use “Fast Operation” when using repeaters

Using Link Check Time and Inactivity Timeout in Single-Connect Mode

If you wish to use the Inactivity Timeout, and the Link Check Time when using Single-Connect Mode, you will need to set both parameters on the same modem.
For example

  1. For the "Single-Connect (Master)" Set the "Link Check Time" to 15 for 15 seconds.
    The Link Check Time is under "Settings">>"S Reg">>"S6-S11"
  2. Set the "Inactivity Timeout" to 30 seconds.
    The Inactivity Timeout is under "Settings">>"Advanced"

I have an error communicating with the 905U-D Modems

If you have configured the modems to "Disable Response Codes" you may have trouble communicating with the 905U-D modem.
Some examples of error messages are:

  • "Error communicating with 905U-D. The module did not respond correctly. Ensure COM port settings are correct, and module is Switched On. (Hint: Set Switch 2 on module to restore factory defaults."
  • "Error communicating with 905U-D. The module did not respond correctly."

To fix this set the 905U-D to factory defaults, then configure the 905U-D modem as required, and choose to "Enable Response Codes"

Connecting to a DT500 in sleep mode

When trying to connect to a DT500 when it is in sleep mode, you may not be able to connect if you have not configured the Link Check Time and the Inactivity timeout.
Follow the steps above for "Auto-Connect Master Configuration" and "Auto-Connect Slave Configuration" to set these parameters.

  • For more information, consult the “Configurations Program”>>“Controlled Mode”>>“Controlled Mode Options” section of the Elpro 905U-D Users Manual.

How do I set the 905U-D Modem to factory defaults?

  1. Disconnect power to the modem
  2. Set the switches on the ‘Aerial’ end of the modem to 0100 (Switch 2 on)
  3. Reconnect the power to the modem
  4. Set the switches back to 0000
  5. Configure the 905U-D modem as required

How can I test the link?

Settings are in the configuration tool, Advanced>>Diagnostics

  1. Conduct RSSI test where the OTHER 905U-D is turned OFF
  2. Conduct RSSI test where the OTHER 905U-D is turned ON, and running Tx BER Test
  3. Do a BER test, set one up to receive, then the other to transmit, view the receive window.
  4. Or set up BER test, selecting “Tx & Rx BER Test”. First, set up the OTHER modem as a REPEATER

What is the ideal signal strength and background noise level?

Background noise level should be no more than approximately -100 dB. Typically -115 dB in urban environment.

Receive signal strength should ideally be around -60 dB (at least in range of -40 to -80 dB). A receive signal strength of -30 dB indicate that the signal is too strong and is swamping the input stage of the radio receiver.

There should be at least a difference of 20-30 dB between the background noise level and the receive signal strength, otherwise the radio will have trouble picking out the the signal from the noise!

"Dialing" Radio modems

I have configured my modems for single connect each with the same system address and a unique Unit address. I do have the modem installed into the Windows TAPI but when I try dialing it won't connect.

On some Windows systems the all the default drivers except the one for "Standard Modem 19200 bps" trys to configure the modems as a FAX. The only work around is to only use the default "Standard Modem 19200 bps" as the hardware type.
Ensure you set the maximum baud rate of the modem as 9600, if using the 905U modems at 9600 baud.

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