More than 20 modules on one place.

Question

Hi to All!
Long time we use XBeeProS1(XBP24-DMSIT-250J) in our product. And is it very good solution. We use this for our pear to pear communication between PC and counter unit (retrofits of measuring machines). Now we have customer with 10 machines/PC in one hall. After first start was data delayed aprox 1 seconds. We try to change "CH" channels and spread channel spectrum for every paired modules and we change NetID according to Serial number of units only for sure. After this is was all perfect. After month started problems on one/two machines with delayed data transmit as previous without spread channels.. In this company they have WiFi routers too. I am sure that problem will be in interference of routers and XBee in particular channel. Can you confirm me this possibility and how to solve this problem? We never solve this before and customer is 900km away. My idea is use combination of modules on low frequency as 800MHz or similar. Thank You for Your interest.
B.R. A.Czadek

Table of channels and NetID, "Names" and "SN:" was not used in setup of modules.
SN: Name: CHannel NetID
99 AX3_DM24-Analog(11uA) 0C 2099
100 AX3_DM24-Analog(11uA) 0D 2100
101 AX3_DM24-Analog(11uA) 0E 2101
102 AX3_DM24-Analog(11uA) 0F 2102
103 AX3_DM24-Analog(11uA) 10 2103
104 AX3_DM24-Analog(11uA) 11 2104
105 AX3_DM24-Analog(11uA) 12 2105
106 AX3_DM24-Analog(11uA) 13 2106
107 AX3_DM24-Digital(TTL) 14 2107
108 AX3_DM24-Digital(TTL) 15 2108

Answer 1

IF this is a point to point connection, the why are you using the Mesh firmware for it? Why are you not using the 802.15.4 code and point to point using the 64 bit addressing? You could have up to 80K worth of throughput on that one channel.

Comments

Yes it's good idea use directly developed module to peer-to-peer. I don't know why I dont'use them. Maybe, because we start working with Maxstream modules and today is it Digi? I am not sure if its directly type helps us. Did you try this communication with more modules? 2,4Ghz spaces is itended for wifi, bluetooth and more devices. 802.11 has only 16 channels? Devices on the same channels can not work in the same time. If we have router which download data and is working on the same channel, it not allow communicate to another devices. I think it's our base problem. Digimesh has 64bit adress too and throuput is based by my 9,6kbps speed of serial line. Now I see at XCTU prog and XBP24(802.15.4ch. num.) has only 12 channels. Default set is "C" hex channel. When we had this channel for all modules. Cmmunicataion was aprox 1s delayed as I told in Previous email. After using separately channels we get aprox 75ms delay (30ms is delay in unit to get data from CPLD, it means 45ms is delay of communiaction) and it works for 14 day without problem? I am sure that 802.15.4 not solve this problem.

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Whether you use Digi Mesh or 802.15.4, they are still a 2.4GHz product using the same band as WIFI and Blue Tooth.  Just note that while they use the same frequency band, how the RF is generated, what data rates and what exact frequency used is all different between each one of the standards.

Remember, you were using a Mesh protocol before which has large delays in it. The 802.15.4 protocol has considerably less over head.

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Is a lot of studies about co-existence in 2,4GHz band between bluetooth, 802.15.4 and WiFi. It will be fine to find anyone who has more experiences with lot of XBEE modules working in the same time, or any docu that would help me.

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I am not sure I understand what it is you are looking for.  Can you re-phrase your question?