XTH9-MI-128 Digi International/Maxstream, XTH9-MI-128 Datasheet - Page 34

• Manufacturer Part Number: XTH9-MI-128
• Description: MODULE RF 900MHZ 1W 115K W/MMCX
• Manufacturer: Digi International/Maxstream

Specifications of XTH9-MI-128

• Frequency: 900MHz
• Data Rate - Maximum: 230kbps
• Modulation Or Protocol: FHSS, FSK
• Power - Output: 30dBm
• Sensitivity: -110dBm
• Voltage - Supply: 3.3V, 5V
• Current - Receiving: 80mA
• Current - Transmitting: 260mA
• Data Interface: Connector, 2 x 10 Header
• Antenna Connector: MMCX
• Operating Temperature: -40°C ~ 85°C
• Package / Case: Module
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Applications: -
• Memory Size: -

XTend™ RF Module ‐ Product Manual v2.x6x
RO (Packetization Timeout) Command
RP (RSSI PWM Timer) Command
<Serial Interfacing> The RO command is used to
set/read the Packetization Timeout setting. RF
transmission begins when data is in the DI buffer
and either of the following criteria are met:
RB and RO criteria only apply to the first packet of
a multi-packet transmission. If data remains in
the DI Buffer (UART receive) after the first packet, transmissions will continue in a streaming man-
ner until there is no data left in the DI Buffer.
When RO is the transmission-beginning criteria: The actual time between the reception of
the last character from the UART and the beginning of RF transmission will be at least 800 µsec
longer than the actual RO time to allow for transmission setup. Additionally, it is subject to 100-
200 µsec of additional uncertainty, which could be significant for small values of RO at high UART
bit rates.
The correct UART character time (10, 11, or 12 bits) is calculated based on the following criteria:
<Diagnostics> RP Command is used to enable a
PWM ("Pulse Width Modulation") output on the
Config/RSSI pin (pin 11 of the RF Module). The
pin is calibrated to show the difference between
received signal strength and the sensitivity level
of the RF module. PWM pulses vary from zero to
95 percent. Zero percent means the received RF
signal is at or below the published sensitivity level
of the module.
The following table shows dB levels above sensitivity and PWM values (The total time period of the
PWM output is 8.32 ms. PWM output consists of 40 steps and therefore the minimum step size is
0.208 ms.):
Table 3‐01. PWM Values
A non-zero value defines the time that PWM output is active with the RSSI value of the last
received RF packet. After the set time when no RF packets are received, PWM output is set low (0
percent PWM) until another RF packet is received. PWM output is also set low at power-up. A
parameter value of 0xFF permanently enables PWM output and always reflects the value of the last
received RF packet.
The Config/RSSI pin is shared between PWM output and Config input. When the module is pow-
ered, the Config pin is an input. During the power-up sequence, if RP parameter is a non-zero
value, the Config pin is configured as an output and set low until the first RF packet is received.
With a non-zero RP parameter, the Config pin is an input for RP ms after power up.
© 2010 Digi Internatonal, Inc.
• RO character times of silence on the UART
• RB characters have been received by the
• 1 start bit
• 8 data bits
• 0 or 1 parity bit [as determined by the NB (Parity) Command)
• 1 or 2 stop bits [as determined by SB (Stop Bits) Command]
receive lines (after receiving at least 1 byte)
UART
dBm above sensitivity
10
20
30
(high period / total period)
PWM percentage
AT Command: ATRO
Binary Command: 0x21 (33 decimal)
Parameter Range:0 - 0xFFFF
Default Parameter Value: 3
Number of bytes returned: 2
Related Commands: RB (Packetization
Threshold)
AT Command: ATRP
Binary Command: 0x22 (34 decimal)
Parameter Range:0 - 0xFF
Default Parameter Value: 0x20 (32d)
Number of bytes returned: 1
20%
35%
50%
[ x UART character times ]
[x 100 milliseconds]
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