XBee3 Cellular LTE-M/NB-IoT Global
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Customer Release Notes
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Copyright (C) 2018, Digi International, Inc.

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### Overview:

These release notes document changes made to the XBee Cellular.

### Compatible Hardware:

* Digi XBee3 Cellular LTE-M/NB-IoT Global

### Links:

[Product Information](https://www.digi.com/lp/digi-xbee-cellular)

### Current Known Issues / Errata:

* 3100 Intermittent failure to go to sleep or wake up when using pin sleep
       with the SPI_nSSEL line while in SPI mode

* 3359 The cellular component does not support hardware flow control internally;
       as a result, RTS (DIO6) and CTS (DIO7) cannot be relied upon for
       flow control in bypass operating mode.
       
* 3362 The underlying modem sometimes buffers returned data on SSL/TLS
       connections. A work-around is to transmit an additional data byte
       to flush the buffer.

* 3400 Sending a TX Request API frame for the TLS protocol with the
       close flag and containing one or more bytes of payload data may
       result in data loss. The workaround is to split the data
       transmission and use a TX Request with no payload to close the
       socket.

* 3494 Loss of signal after multiple attempts to rejoin the network
       will result in entering an Out-of-Service mode where no network
       registration or data transfer will be attempted for four
       minutes.

* 3499 A race condition exists that will reduce the number of
       available sockets when a socket is closed while data is in
       flight. The workaround is to reboot the XBee if a persistent
       error is received on attempts to open new sockets.

* 3500 When in API mode, multiple incoming connections to a listening
       socket over the maximum allowed will result in attempts to
       connect being rejected. Incoming connections made once
       established connections are closed will not be properly
       reported through API frames. Avoid making multiple simultaneous
       incoming connections to the XBee.

* 3736 Server certificates programmed previously on the system may
       still be used to authenticate servers despite configuration
       change or being removed from the file system.

* 3750 Sending an SMS message will not wake the cellular component
       from PSM sleep

* 3753 Internal logic can interfere with USB operation in direct USB
       mode when configured for anything other than bypass (AP=5)

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### Release Version

1140C - XBee3 Cellular LTE-M/NB-IoT Global

### Release Date

* September 2018

### New Features:

* NB-IoT Support
    * Support for European and U.S. Carriers.
    * Important: Conditionally approved for use on T-Mobile NB-IoT network for 
      evaluation and development purposes. Full certification will be completed 
      with an upcoming cellular component firmware update (SARA-R410M-03B). 
      Contact Digi sales for more information.
    * Added new option 1 to CP command for network configuration. 
    * Added new commands BM, BN to select band mask.
    * Added new command N# to select network preference.
    
### Bug Fixes (XBCELL):

* 3861 Fixed issues with a memory leak when using TLS mutual authentication 
       and additional sockets cannot be opened.
* 4091 Sequence to initially connect to cellular network improved.
    
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### Release Version

1140B - XBee3 Cellular LTE-M/NB-IoT Global

### Release Date

* June 2018

### New Features:

* File system support
    * ATFS command to access through Command Mode
    * MicroPython file interfaces for programmatic access
    * Provides MicroPython module import support
    * Allows storage of TLS certificates for authentication
    * Secure encrypted file storage to protect MicroPython code and
      TLS private keys

* TLS Authentication
    * Accessed in MicroPython with the ussl.wrap_socket method
    * Configurable with the $0/$1/$2 commands
    * Uses certificates stored on the file system
    * New API frame 0x23 to access multiple authentication profiles

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### Release Version:

* 1140A - XBee3 Cellular LTE-M/NB-IoT Global

### Release Date:

* May 2018

### New Features:

* Initial release
* Key features:
    * Digital I/O support
    * Analog Input support
    * API & Transparent mode
    * AT command mode
    * By-pass to raw cellular modem
    * SMS
    * TCP/UDP (up to six sockets)
    * TLS (up to six sockets)
    * Incoming connections
    * MicroPython!
        * On-module programmability to add local intelligence
        * Many examples in the Digi MicroPython Programmer Guide
        * AT commands for managing run-time behavior
    * Low power modes
        * LTE power save mode (PSM)
        * Deep sleep mode
        * Pin sleep support
        * Cyclic sleep support
        * Airplane mode support
    * Digi TrustFence secure boot
    * SMS UTF-16/UCS-2 encoding support
    * Multi-network capability (Verizon, AT&T, ...)
    
### Bug Fixes (XBCELL):

* 3506 When a transmission wakes the cellular component from the PSM
       sleep state, it is possible for the transmission to fail while
       network registration is being confirmed and retry may be
       necessary.