X09-009PKC-RA Digi International/Maxstream, X09-009PKC-RA Datasheet - Page 48

• 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]
5.3.2. Multi-Streaming Mode
Theory of Operation
Characteristics:
definition]
Required Parameter Values (TX Modem): MD = 1 (Base), MD = 2 (Remote), RN > 0, RR > 0,
MY ≠ 0xFFFF
Recommended Use: Use this mode in point-to-multipoint networks where remote modems
initiate communications and require exclusive (uninterrupted) connections to the base modem.
Table 5.5.
Modem
Base
Remotes
* When Multi‐Streaming is enabled, the following parameters are consequently modified (if they have not
already been modified from their default states): RR, RN, MY, CD, AT and BT. [refer to Table 5.6]
When in Multi-Streaming Mode, all remote modems can initiate communications with the base
modem at the same time, but only one remote is granted an exclusive connection. After an
exclusive connection begins, data is transferred exclusively between two modems without
interruption from any other modems in the network.
An exclusive connection is a bi-directional connection that can only be established when in Multi-
Streaming Mode. An exclusive connection is immune to other remote modems interrupting the
connection and interleaving data (The interleaved data potentially renders the base modem
unable to discern from which remote modem the data was transmitted).
When an exclusive connection is granted to a single remote, the other remotes are notified that
the connection exists. The notification causes the remote modems to postpone transmissions
until the base modem sends notification that the exclusive connection has ended.
Figure 5.7.
In the connection sequence above, an exclusive connection is first granted to “Remote m”. The
CGP (Connection Grant Packet) is broadcast to all remote modems in the network to
communicate the base in engaged in an exclusive connection. Upon receipt of the CGP
notification, remote modems will wait for a DGP (Disconnect Grant Packet) before attempting
again to send data to the base modem.
Sample Network Profile
Sample Connection Sequence Diagram
Enables exclusive connections [refer to Theory of Operation section for
Supports the passing of large data streams (> 256 bytes) from multiple
remote modems to a base modem (If a complete data stream from a remote
modem is less than 256 bytes, data can be sent from several remotes to a
base location without enabling this mode and latencies will be much less.)
Transmissions never acknowledged (ACK) by receiving modem(s)
Parameter Settings (assume default values for parameters not listed)
ATMD 1
ATMD 2
[configure modem as Multi-Stream Base] *
[configure modem as Multi-Stream Remote] *
CRP = Connection Request Packet
CGP = Connection Grant Packet
DRP = Disconnect Request Packet (not
shown in diagram – applicable when
remote connection is disconnected using
the pin sleep I/O line.
DGP = Disconnect Grant Packet
ACK = Acknowledgement of reception.
Base modem = The central
transmitting/receiving modem in a network
of modems that maintains communications
with remote modems.
Remote modem = A modem in a network
that sends data to and receives data from a
base modem.
Payload = Data contained inside the RF
Data of the RF Packet that originates from a
host to be transmitted over‐the‐air.
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