X09-009PKC-RA Digi International/Maxstream, X09-009PKC-RA Datasheet - Page 42

• Manufacturer Part Number: X09-009PKC-RA
• Description: MOD RF 900MHZ 9600BPS RS232/485
• Manufacturer: Digi International/Maxstream
• Series: XStream™r

Specifications of X09-009PKC-RA

• Function: Transceiver, FHSS
• Modulation Or Protocol: FHSS, FSK
• Frequency: 900MHz
• Applications: ISM
• Interface: RS-232, RS-485
• Sensitivity: -110dBm
• Power - Output: 20dBm (100mW)
• Data Rate - Maximum: 10 kbps
• Voltage - Supply: 7 V ~ 18 V
• Package / Case: Module
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -

© 2006 MaxStream, Inc. Confidential & Proprietary
XStream‐PKG‐R™ RS‐232/485 RF Modem – Product Manual v5.x00 [2006.02.24]
5.2. Basic Communications
5.2.1. Streaming Mode (Default)
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
communications, meaning that the RF link simply replaces a wired link.
Characteristics:
Required Parameter Values (TX Modem): 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.
Streaming Mode Data Flow
Figure 5.4.
Events and processes in this mode are common to all of the other RF
Communication Modes.
NOTE: When streaming data, RB and RO parameters are only observed on
the first packet.
After transmission begins, the TX event will continue uninterrupted until
the DI buffer is empty or the streaming limit (TT Command) is reached.
As with the first packet, the payload of each subsequent packet includes
up to the maximum packet size (PK Command).
The streaming limit (TT Command) is specified by the transmitting
modem as the maximum number of bytes the transmitting modem can
send in one transmission event. After the TT parameter threshold is
reached, the transmitting modem 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 receiving
modems stay synchronized with the transmitting modem for the
duration of the transmission event (from preceding packet information).
However, due to interference, some receiving modems may lose data
(and synchronization to the transmitting modem), particularly during
long transmission events.
Once the transmitting modem has sent all pending data or has reached
the TT limit, the transmission event ends. The transmitting modem will
not transmit again for exactly RN delay slots if the local (i.e.
transmitting modem’s) RN parameter is set to a non-zero value. The
receiving modem(s) will not transmit for a random number of delay
slots between 0 and (RN-1) if the local (i.e. receiving modem’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 transmitting modem, during which several receiving modems
may have become ready to transmit.
• Broadcast - By default, XStream Modems communicate through Broadcast communications
• Addressed - If addressing parameters match, received RF data is forwarded to the DO (Data
and within a peer-to-peer network topology. When any modem transmits, all other modems
within range will receive the data and pass it directly to their host device.
Out) buffer; otherwise, the RF data is discarded.
Streaming Mode State Diagram (TX Modem)
Highest data throughput
Lowest latency and jitter
Reduced immunity to interference
Transmissions never acknowledged (ACK) by receiving modem(s)
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