This test is designed to allow the user to quickly establish a functional ZigBee Networking Range Test. While this article was originally written for a ZigBee mesh network, the same basic steps can be done using a Digi Mesh network.
Minimum required amount of hardware to run a ZigBee Range Test:
- Three XBee modules, two loaded with XBee ZigBee Router AT Firmware and one loaded with XBee ZigBee Coordinator AT Firmware. It is best if the Coordinator is programmed on a module that has a U.FL connector (XB24-AUI-001).
- Three Interface Boards (XBIB-R or -U) at least one of them should be an XBIB-R.
- One PC running Win XP with an available serial port, with X-CTU installed. X-CTU can be download from the Digi website here.
- Assorted serial/USB cables, loopback adapter and batteries for moving about.
Open up two X-CTU sessions. Under the PC Settings tab select a different COM port for each session. Move to the Terminal tab. This will open the two separate COM ports for each terminal. From the Terminal tab, AT command can be sent to the radio attached to the specificed COM port to change settings. The terminal will be used to send AT commands to correctly configure the Router and Coordinator parameters.
Note: In the example below, sequences in blue are information sent to the RF module as seen from an X-CTU Terminal screen. Sequences in red are representative of the RF module''''s responses as shown from X-CTU.
On the Coordinator type the following AT command string:
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| OK |
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| ATNICOORD |
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| OK |
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| ATWR |
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| OK |
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| ATCN |
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| OK |
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On the Router(s) type the following AT command string:
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| OK |
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| ATNIREMOTEx // (Where x is 1 or 2 for the corresponding Router) |
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| OK |
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| ATWR |
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| OK |
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| ATCN |
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| OK |
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Now set the COORD to communicate with REMOTE1, on the Coordinator type:
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| OK |
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| ATND // (This will report back all nodes on your network) |
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| OK |
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| ATDNREMOTE1 ... // (The Extended and Network addresses of REMOTE1 are reported) |
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| OK // (After a DN the XBee exits AT command mode automatically) |
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You will notice that REMOTE1 & REMOTE2 are automatically addressed to send data back to the COORDINATOR. Run a range test with the loopback adapter connected up to REMOTE1, you should be getting good results.
Now you are ready to add Mesh Networking to your range test:
- Go to the Range Test tab in the X-CTU software.
- Go to Advanced>>> and change Data receive timeout to 5000, turn off REMOTE2, and restart the Range Test.
- Then move REMOTE1 out of range of the COORD (this can most easily done by removing the antenna attached to the U.FL antenna on the COORD).
- Stop the Range Test.
- Power REMOTE2 back on and wait for it to join (when the red power LED starts blinking again). If you didnt have a U.FL connector on the COORD then you must place REMOTE2 in a position halfway between COORD and REMOTE1.
- Start the Range Test over.
Notice that it takes several seconds to establish a link (thats why we changed Data receive timeout), but after the first pause the Range Test should resume normal speed. This is because initially the COORD had to perform a Route Discovery. If you turn off REMOTE2 the Range test should start to fail.
NOTE: Apart from this method, Zigbee modules provide one more method to perform range test with help of 'Cluster ID' parameter. Click here for details of this method.