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. 46
Basic Communications
Basic Communications are accomplished through two sub-types:
• Broadcast - By default, XTend RF Modules communicate through Broadcast communications
and within a peer-to-peer network topology. When any module transmits, all other modules
within range will receive the data and passit directly to their host device.
• Addressed - If addressing parameters match are in order, received RF data is forwarded to the
DO (Data Out) buffer; otherwise, the RF data is discarded.
When using Basic Communications, any functions such as acknowledgements are handled at the
application layer by the integrator. The Broadcast Modes provide transparent communications,
meaning that the RF link simply replaces a wired link.
Streaming Mode (Default)
Characteristics:Highest data throughput
Lowest latency and jitter
Reduced immunity to interference
Transmissions never acknowledged (ACK) by receiving module(s)
Required Parameter Values (TX module): RR (Retries) = 0
Related Commands: Networking (DT, MK, MY), Serial Interfacing (PK, RB, RO, TT)
Recommended Use: Mode is most appropriate for data systems more sensitive to latency and/or
jitter than to occasional packet loss. For example: streaming audio or video.
Connection Sequence
Figure4‐04. StreamingModeStateDiagram(TXModule)
• Events & processes in this mode are common to all of
the other RF Modes.
• When streaming data, RB and RO parameters are only
observed on the first packet.
After transmission begins, the transmission event will
continue uninterrupted until the DI buffer is empty or the
streaming limit (TT parameter) is reached. As with the first
packet, the payload of each subsequent packet includes up
to the maximum packet size (PK parameter).
The TT parameter (streaming limit) is specified by the TX
(transmitting) module as the maximum number of bytes the
TX module can send in one transmission event. After the TT
parameter threshold is reached, the TX module will force a
random delay of 1 to RN delay slots (exactly 1 delay slot if
RN = 0).
Subsequent packets are sent without an RF initializer since
RX (receiving) modules remain synchronized with the TX
module for the duration of the transmission (from preceding
packet information). However, due to interference, some RX
modules may lose data (and synchronization to the TX
module), particularly during long transmission events.
Once the TX module has sent all pending data or has
reached the TT limit, the transmission event ends. The TX
module will not transmit again for exactly RN delay slots if
the local (i.e. TX module's) RN parameter is set to a non-
zero value. The RX module(s) will not transmit for a random
number of delay slots between 0 and (RN-1) if the local (i.e.
receiving module's) RN parameter is set to a non-zero
value. These delays are intended to lessen congestion
following long bursts of packets from a single TX module,
during which several RX modules may have become ready to transmit.