XTIB-R Digi International/Maxstream, XTIB-R Datasheet - Page 45

• Manufacturer Part Number: XTIB-R
• Description: BOARD INTERFACE 1W RS232/485
• Manufacturer: Digi International/Maxstream

Specifications of XTIB-R

• Accessory Type: Interface Board
• For Use With/related Products: XTend Radios
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: Q2172356

9XTend™ OEM RF Module ‐ Product Manual v2.x4x [2007.01.04]
4.2. Basic Communications
4.2.1. Streaming Mode (Default)
Connection Sequence
Basic Communications are accomplished through two sub-types:
When using Basic Communications, any functions such as acknowledgements are handled at the
application layer by the OEM/integrator. The Broadcast Modes provide transparent communica-
tions, meaning that the RF link simply replaces a wired link.
Characteristics: Highest data throughput
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.
Figure 4‐04. Streaming Mode State Diagram (TX Module)
After transmission begins, the transmission event will con-
tinue 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 mod-
ule), 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 fol-
lowing long bursts of packets from a single TX module, dur-
ing which several RX modules may have become ready to transmit.
© 2007 MaxStream, Inc.
• Broadcast - By default, XTend RF Modules communicate through Broadcast communications
• Addressed - If addressing parameters match are in order, received RF data is forwarded to the
• Events & processes in this mode are common to all of
• When streaming data, RB and RO parameters are only
and within a peer-to-peer network topology. When any module transmits, all other modules
within range will receive the data and pass it directly to their host device.
DO (Data Out) buffer; otherwise, the RF data is discarded.
the other RF Modes.
observed on the first packet.
Lowest latency and jitter
Reduced immunity to interference
Transmissions never acknowledged (ACK) by receiving module(s)
Chapter 4 ‐ RF Communication Modes
45