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Friday, March 18, 2011

Running RS 422 / 485 on an XTend Digimesh 8053 Network

You find yourself with a bunch of RS-422 / 485 devices located in multiple locations, some of which have no clear line of sight back to your base of operations.......what to do!?
Oh, and just for fun, some of the distances are >1 mile.
Use a wireless mesh network.

I had to create a test for this so I got busy.

To accomplish this, I used the following:

    List of components:

  1. 2 x B&B RS-232 to RS-422/485 Converter (Model: 4WSD9R)
  2. 2 x Digi RS-232 / 422 / 485 Interface Board (Model: XTIB-R)
  3. 1 x Digi USB Interface Board (Model: XTIB-U)
  4. 3 x Digi XTend Module (Model: XT09-MI) (FW: 8053)
  5. 4 x RJ485 to Serial adapter
  6. 2 x Cat5e patch cable
  7. 2 x Computer with RS-232 ports and XCTU installed (a terminal program can be used in lieu of XCTU)
  8. 2 x Standard Serial Cable (RS-232 with DB9 connector)


    The Setup

    This test has 3 parts to it:

    1

    RS-232

    2

    RS-485 4 Wire

    3

    RS-422 4 Wire

    To begin the test, the first thing that must be done is to ensure all components are

    setup for RS-485 4 wire.

    Each module must have the CS parameter set to 3, just in case the DIP switches don't initialize the change of this parameter automatically.

    All modules are set to the same Modem VID, Channel and all use the broadcast mode for their addressing. (please refer to attached profiles)

    2 computers were used that had XCTU loaded and all firmware libraries updated to the latest firmware versions to ensure that the modules could be read properly.

    The 3 profiles are included for test purposes. These can be loaded into X-CTU and uploaded to the modules to ensure exact replication of test parameters.



NOW TO THE TEST!!!!!!


    The Test: Part 1 (RS-232)


    This part only requires radios, computers and RS-232 serial cables for hardware.


    This test was conducted as follows:

  1. Load each module, while in RS232 mode, with appropriate profile. (XT09 DIP switch settings will be 1,5,6 ON for this portion of the test)
  2. Test communications between the Base and the Remote, leaving the
  3. Repeater out of the equation. This was done by opening the terminal on each computer and passing packets of characters back and forth.

  4. Remove Antenna from Base and Remote radios. Verify that communication is NON-functional.(These radios have no antennae and their power setting (PL) is a 0)
  5. Power on the Repeater Node.(This node has an antenna and power setting (PL) of 4)
  6. Start transmitting data from Base to Remote. (There will be a delay at the beginning. This is due to the network establishing routes + the latency of having a repeating node in a network)
  7. Transmit from Remote to Base for 2 way communication verification.



    The Test: Part 2 (RS-485 4 Wire)

    This part only requires all hardware components listed above..

    This test was conducted as follows:

  1. XT09 DIP switch settings will be 2,5,6 ON for this portion of the test
  2. Connect ALL hardware as shown on the diagram.
  3. B&B adapter will have DIP switch 1 ON, the rest OFF.
  4. Test communications between the Base and the Remote, leaving the
  5. Repeater out of the equation. This was done by opening the terminal on each computer and passing packets of characters back and forth.

  6. Remove Antenna from Base and Remote radios. Verify that communication is NON-functional (These radios have no antennae and their power setting (PL) is a 0)
  7. Power on the Repeater Node (This node has an antenna and power setting (PL) of 4)
  8. Start transmitting data from Base to Remote. (There will be a delay at the beginning. This is due to the network establishing routes + the latency of having a repeating node in a network)
  9. Transmit from Remote to Base for 2 way communication verification.

    The Test: Part 3 (RS-422 4 Wire)

    This part only requires all hardware components listed above..

    This test was conducted as follows:

  1. XT09 DIP switch settings will be 2,5,6 ON for this portion of the test
  2. Connect ALL hardware as shown on the diagram.
  3. B&B adapter will have ALL DIP switches OFF.
  4. Test communications between the Base and the Remote, leaving the
  5. Repeater out of the equation. This was done by opening the terminal on each computer and passing packets of characters back and forth.

  6. Remove Antenna from Base and Remote radios. Verify that communication is NON-functional (These radios have no antennae and their power setting (PL) is a 0)
  7. Power on the Repeater Node (This node has an antenna and power setting (PL) of 4)
  8. Start transmitting data from Base to Remote. (There will be a delay at the beginning. This is due to the network establishing routes + the latency of having a repeating node in a network)
  9. Transmit from Remote to Base for 2 way communication verification.