• State
  • Locked Locked
  • Replies 3 replies
  • Subscribers 54 subscribers
  • Views 494 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

CC1101 R mode channels

jagadeesh kumar1
Intellectual 405 points
Other Parts Discussed in Thread: CC1101, MSP430F5528

hi all,

  

     I am using  msp430f5528 processor with CC1101 transciver i am planning to run my master in R mode. but for R mode in cc1101 we have 10 channels each channel having different frequency.but i can able to receive data from only one meter.if i want to receive data from all R mode meters which are running in different channels what should i do. through CHANNR register I can select only one channel.and i can communicate with the meters which all are there in that channel.if i want to communicate with the meters which are there in other channels also is it is possible?.

 I increased the deviation and RX bandwidth still i m not getting all meters data which are operating in different channels

           thanku

  • 0
    TI__Guru**** 317180 points
    -If you have Meter1 on Channel1, Meter2 on Channel2 and so on you can do the following:
    - First go to Channel1, than Channel2 etc and listen in each channel for a signal. To do this you need to know that only one meter sends at a time to given times
    - Or: Have N receivers, each on it's own channel.
    - Or: Have a RX BW on the receiver that is N*Channelx BW. This reduces the sensitivity and only one meter could send at a given time.

    Note that it more than one meter sends on a channel the receiver won't be able to receive because the data will be on to of each other.
  • 0 in reply to TER
    Intellectual 405 points
    In wireless M-Bus R mode, meters uses frequencies (868.030 + n * 0.06)MHz, max FSK devation 7.2KHz, chiprate is 4.8kcps, channels n = 1-10

    Now I calculate RX filter bandwidth for above parameters 2 * dev + datarate = 2*7.2 +4.8 = 19.2 /0.8 = 24KHz for one channel

    If I want to use it for 10 channels, then it will be N*channelBW = 10 * 24KHz = 240KHz,

    I selected middle frequency (868.030 + n * 0.06) = (868.030 + 5 * 0.06) = 868.33MHz as a base frequency on the receiver device, so that it can receive data from all channels(868.030 - 868.630).

    With the above frequency(868.33MHz) and RX filter bandwidth(240KHz) and deviation (7.2KHz), receiver should receive data from all ten channels but it is not happening ?

    The way I calculated the RX filter bandwidth is wrong ? Please correct me if I am wrong.
  • 0 in reply to jagadeesh kumar1
    TI__Mastermind 39860 points
    The way you estimated RX filter BW based on 10 x (Carson's rule) is correct.

    Using a more accurate calculation tool than Carson's rule the 99% occupied bandwidth is 22 kHz.