User's Manual
Table Of Contents
- 1. XTend RF Module
- 2. RF Module Operation
- 3. RF Module Configuration
- Programming Examples
- Command Reference Table
- Command Descriptions
- %V (Board Voltage) Command
- AM (Auto-set MY) Command
- AP (API Enable) Command
- AT (Guard Time After) Command
- BD (Interface Data Rate) Command
- BR (RF Data Rate) Command
- BT (Guard Time Before) Command
- CC (Command Sequence Character) Command
- CD (GPO2 Configuration) Command
- CF (Number Base) Command
- CN (Exit AT Command Mode) Command
- CS (GPO1 Configuration) Command
- CT (Command Mode Timeout) Command
- DB (Received Signal Strength) Command
- DT (Destination Address) Command
- E0 (Echo Off) Command
- E1 (Echo On) Command
- ER (Receive Error Count) Command
- FH (Force Wake-up Initializer) Command
- FL (Software Flow Control) Command
- FS (Forced Synch Time) Command
- FT (Flow Control Threshold) Command
- GD (Receive Good Count) Command
- HP (Hopping Channel) Command
- HT (Time before Wake-up Initializer) Command
- HV (Hardware Version) Command
- ID (Modem VID) Command
- KY (AES Encryption Key) Command
- LH (Wake-up Initializer Timer) Command
- MD (RF Mode) Command
- MK (Address Mask) Command
- MT (Multi-transmit) Command
- MY (Source Address) Command
- NB (Parity) Command
- PB (Polling Begin Address) Command
- PD (Minimum Polling Delay) Command
- PE (Polling End Address) Command
- PK (Maximum RF Packet Size) Command
- PL (TX Power Level) Command
- PW (Pin Wake-up) Command
- RB (Packetization Threshold) Command
- RC (Ambient Power - Single Channel) Command
- RE (Restore Defaults) Command
- RM (Ambient Power - All Channels) Command
- RN (Delay Slots) Command
- RO (Packetization Timeout) Command
- RP (RSSI PWM Timer) Command
- RR (Retries) Command
- RT (GPI1 Configuration) Command
- SB (Stop Bits) Command
- SH (Serial Number High) Command
- SL (Serial Number Low) Command
- SM (Sleep Mode) Command
- ST (Time before Sleep) Command
- TP (Board Temperature) Command
- TR (Transmit Error Count) Command
- TT (Streaming Limit) Command
- TX (Transmit Only) Command
- VL (Firmware Version - Verbose)
- VR (Firmware Version - Short) Command
- WA (Active Warning Numbers) Command
- WN (Warning Data) Command
- WR (Write) Command
- WS (Sticky Warning Numbers) Command
- API Operation
- 4. RF Communication Modes
- Appendix A: Agency Certifications
- Appendix B: Development Guide
- Appendix C: Additional Information
XTend™RFModule‐ProductManual
©2013DigiInternatonal,Inc. 14
Channel initialization is the process of sending an RF initializer that synchronizes receiving
modules with the transmitting module. During channel initialization, incoming serial data
accumulates in the DI buffer.
RF data, which includes the payload data, follows the RF initializer. The payload includes up to the
maximum packet size (PK Command) bytes. As the TX module nears the end of the transmission,
it inspects the DI buffer to see if more data exists to be transmitted. This could be the case if more
than PK bytes were originally pending in the DI buffer or if more bytes arrived from the UART after
the transmission began. If more data is pending, the transmitting module assembles a subsequent
packet for transmission.
Refer to the ‘RF Communication Modes’ section to view state diagrams that illustrate channel
initialization and the sequence of events that follow.
RF Packet
Figure2‐06. RFPacketComponents
* When streaming multiple RF packets, the RF Initializer is only sent in front of the first packet.
RF Initializer
An RF initializer is sent each time a new connection sequence begins. The RF initializer contains
channel information that notifies receiving modules of information such as the hopping pattern
used by the transmitting module. The first transmission always sends an RF initializer.
An RF initializer can be of various lengths depending on the amount of time determined to be
required to prepare a receiving module. For example, a wake-up initializer is a type of RF initializer
used to wake remote modules from Sleep Mode (Refer to the FH, LH, HT and SM Commands for
more information). The length of the wake-up initializer should be longer than the length of time
remote modules are in cyclic sleep.
Header
The header contains network addressing information that filters incoming RF data. The receiving
module checks for matching a Hopping Channel, VID and Destination Address. Data that does not
pass through all three network filter layers is discarded.
Refer to the ‘Addressing’ section of the “RF Communication Modes” chapter for more information.
CRC (Cyclic Redundancy Check)
To verify data integrity and provide built-in error checking, a 16-bit CRC (Cyclic Redundancy
Check) is computed for the transmitted data and attached to the end of each RF packet. On the
receiving end, the receiving module computes the CRC on all incoming RF data. Received data that
has an invalid CRC is discarded [refer to the ‘Receive Mode’ section].
Receive Mode
If a module detects RF data while operating in Idle Mode, the module transitions to Receive Mode
to start receiving RF packets. Once a packet is received, the module checks the CRC (cyclic
redundancy check) to ensure that the data was transmitted without error. If the CRC data bits on
the incoming packet are invalid, the packet is discarded. If the CRC is valid, the packet proceeds to
the DO Buffer.