ZigBee/IEEE802.15.4 Measurement Tool

This section describes the ZigBee / IEEE802.15.4 Measurement Tool available for ZigBee / IEEE802.15.4 Evaluation and Development Kit.

Network Discovery Tool

Download and Write

• Download (for TWE-EK-002)
• Write NetworkDiscoveryTool_JN5148.bin found in decompressed \Build into the sensor node (large, with the LCD screen).

Communication Quality Evaluation Tool (PER)

Download and Write

• Download (for TWE-EK-002)
• Write AN1006_PER_Master_JN5148.bin found in decompressed JN-AN-1006-PER-Test\AN1006_Master\Build into the wireless sensor node (large, with the LCD screen).
• Similarly, write AN1006_PER_Slave_JN5148.bin found in JN-AN-1006-PER-Test\AN1006_PER_Slave\Build into the wireless sensor node (small, without the LCD screen).

Execution

• Power on the wireless sensor node (large, with the LCD screen) and the wireless sensor node (small. Without the LCD screen).
• The wireless sensor node (large, with the LCD screen) allows you to complete basic settings by means of menu manipulation on the screen.
  *Set the Power Mode to High if you use TWE-001 STRONG.

  Options
  Channel:            11         <- Test channel (26 cannot be selected)
  Power Mode:     Low   <- Low for TWE-001, or High for TWE-001 STRONG
  Power Level:      24      <- Output attenuator (24=-0db, 16=-11.5db, 8=-23db, and 0=-34.5db)
  Retries:                3        <- Number of retries in the MAC layer
  LEDs:                   Enabled
  Done                              <- Test started
  Up                Down          Select
  Button1       Button2       Button3

• Select items using Buttons 1 and 2, and change values with Button 3. When setting is completed, move to "Done" and press Button 3.
• When communication with the wireless sensor node (small, without the LCD screen) is checked, the following screen appears:

  Channel:            11          <- Test channel (26 cannot be selected)
  Mode:                 Ack      <- Communication mode (Ack or No Ack)
  Seen:                 5590   <- Number of successful communications
  Total:                  5635    <- Number of communications
  PER %:               0.8      <- Packet error rate
  CCA Fail %        0.0      <- CCA fail rate
  Retries               3           <- Retry setting
  Chan                Stop          Mode
  Button1       Button2       Button3

Start Measurement

• Place the wireless sensor node (small, without the LCD screen) at the measuring point.
• Set the wireless sensor node (large, with the LCD screen) well close to the wireless sensor node (small, without the LCD screen). (Set the channel mode and start PER measurement)
• Move the wireless sensor node (large, with the LCD screen) to the other measuring point such that radio waves are not disconnected wherever possible.
• Press Button 2 (STOP/START) to suspend measurement.
• Press Button 2 again to restart measurement (statistic information will be initialized).
  *The longer the distance is, the longer it takes time to restart, which could lead to time-out. In this case, repeat suspension and restart several times.
  *If nothing occurs, go back to the setup process. Involving several communications, the setup process might fail where the packet error rate is high. Therefore, it might be effective to move a little closer to the sensor node for setup and then go away from the node.
• When the counter Seen counts up to a given number, press Button 2 to suspend measurement and record the measured value.
• Move to the next measuring point.

Other Information

• The difference between the Ack and NoAck modes is which of the two nodes to send packets first.
  Ack: Communication to send packets from the wireless sensor node (large, with the LCD screen), receive the packets with the wireless sensor node (small, without the LCD screen), and then receive ACK.
  NoAck: Communication to send packets from the wireless sensor node (small, without the LCD screen) without Ack, and see how many times the packets are received with the wireless sensor node (large, with the LCD screen).
  *This measurement is also effective where operation is unstable. However, it cannot directly compare the values with those of the Ack mode.
• If you want to measure a new PER, stop measurement (with Button 2) and then press Start (Button 2) again. This process resets the counter and communication restarts.
• Communication could not successfully start in the poor communication condition. Move to the location with a better communication condition to check that communication starts, and then move to the measuring location.
• The packet size at the data payload area is 4 bytes, and the total packets account for 23 bytes.
  *Details: Header in the PHY layer of 6 bytes / header in the MAC layer of 11 bytes (source: short, destination: short) / data payload of 4 bytes / FCS of 2 bytes = total 23 bytes

Measurement Precautions

• The signal range is also affected by surrounding noise. If the distance cannot be longer where there are not many obstacles, check the condition of radio waves using the network discovery tool. Changing the communication channel to a location with low noise could improve communication quality.