X09-019WNC Digi International/Maxstream, X09-019WNC Datasheet - Page 42

• Manufacturer Part Number: X09-019WNC
• Description: MOD RF 900MHZ 19.2K W/WIRE ANT
• Manufacturer: Digi International/Maxstream
• Series: XStream™r

Specifications of X09-019WNC

• Frequency: 900MHz
• Data Rate - Maximum: 19.2kbps
• Modulation Or Protocol: FSK
• Power - Output: 100mW
• Sensitivity: -110dBm
• Voltage - Supply: 5V
• Current - Receiving: 50mA
• Current - Transmitting: 140mA
• Data Interface: PCB, Through Hole
• Antenna Connector: On-Board, Wire Antenna
• Operating Temperature: 0°C ~ 70°C
• Package / Case: Module
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Applications: -
• Memory Size: -

XStream™ OEM RF Module – Product Manual v5.x00 [2006.02.24]
After receiving and acknowledging a packet, the receiving module will move to the next
frequency and listen
for either a retransmission or new data for a specific period of time. Even if
the transmitting module has indicated that it has no more pending transmit data, it may have not
received the previous ACK, and so it may retransmit the packet (potentially with no delay after
the ACK slot). In this case, the receiving module will always detect the immediate retransmission,
which will hold off the communications channel and thereby reduce collisions. Receiving modules
acknowledge each retransmission they receive, but they only pass the first copy of a packet they
receive out the UART.
RB and RO parameters are not applied to subsequent packets. This means that once transmission
has begun, it will continue uninterrupted until the DI buffer is empty or the streaming limit (TT)
has been reached. As with the first packet, the payload of each subsequent packet includes up to
the maximum packet size (PK parameter). The transmitting module checks for more pending
data near the end of each packet.
The streaming limit (TT parameter) specifies the maximum number of bytes that the transmitting
module will send in one transmission event, which may consist of many packets and retries. If
the TT parameter is reached, the transmitting module will force a random delay of 1 to RN delay
slots (exactly 1 delay slot if RN is zero). Each packet is counted only once toward TT, no matter
how many times the packet is retransmitted.
Subsequent packets in acknowledged mode are similar to those in streaming mode, with the
addition of an acknowledgement between each packet, and the possibility of retransmissions.
Subsequent packets are sent without an RF initializer, as the receiving modules are already
synchronized to the transmitting module from the preceding packet(s) and they remain
synchronized for the duration of the transmission event. Each retransmission of a packet includes
an RF initializer.
Once the transmitting module has sent all pending data or has reached the TT limit, the
acknowledged transmission event is completed. The transmitting module will not transmit again
for exactly RN delay slots, if the local RN parameter is set to a nonzero value. The receiving
module will not transmit for a random number of delay slots between 0 and (RN-1), if the local
RN parameter is set to a nonzero value. These delays are intended to lessen congestion following
long bursts of packets from a single transmitting module, during which several receiving modules
may have themselves become ready to transmit.
© 2006 MaxStream, Inc. Confidential and Proprietary
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