XStream
‐
PKG
‐
T™
Telephone
RF
Modem
–
Product
Manual
v5.x00
[2006.02.24]
RO (Packetization Timeout) Command
©
2006
MaxStream,
Inc.,
Confidential
and
Proprietary
56
<Serial Interfacing> RO Command is used to
specify the timeout value (in 0.2 ms increments)
when transmission starts after receiving serial
data. If the RB = 0, this command has no effect.
After a serial byte is received and if no other byte
is received before the RO timeout, the
transmission will start.
RF transmission will commence when data is in
the DI Buffer and either of the following criteria are met:
AT Command: ATRO
Binary Command: 0x21 (33 decimal)
Parameter Range: 0 – 0xFFFF [x 200 µs]
Default Parameter Value: 0x32 (50 decimal)
Number of bytes returned: 2
Related Commands: RB (Packetization
Threshold)
Minimum Firmware Version Required: 4.2AA
•
RO times out on the UART receive lines (ignored if RO = 0)
•
RB characters have been received by the UART (ignored if RB = 0)
RP (RSSI PWM Timer) Command
<Diagnostic> RP Command is used to enable a
PWM (“Pulse Width Modulation”) output on the
Config pin (pin 9 of the RF Module) which is
calibrated to show the level the received RF
signal is above the sensitivity level of the radio
modem. The 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 radio modem. The following table shows
levels above sensitivity and PWM values.
AT Command: ATRP
Binary Command: 0x22 (34 decimal)
Parameter Range: 0 - 0x7F
[x
100
milliseconds]
Default Parameter Value: 0 (disabled)
Number of bytes returned: 1
Minimum Firmware Version Required: 4.2AA
The total period of the PWM output is 8.32 ms. There are 40 steps in the PWM output and
therefore the minimum step size is 0.208 ms.
dBm above Sensitivity
PWM percentage
(high period / total period)
10 47.5
20 62.5
30 77.5
A non-zero value defines the time that the PWM output will be active with the RSSI value of the
last received RF packet. After the set time when no RF packets are received, the PWM output will
be set low (0 percent PWM) until another RF packet is received. The PWM output will also be set
low at power-up. A parameter value of 0xFF permanently enables the PWM output and it will
always reflect the value of the last received RF packet.
PWM output shares the Config input pin. When the radio modem is powered, the Config pin will
be an input. During the power-up sequence, the Config pin will be read to determine whether the
radio modem is going into AT Command Mode. After this, if RP parameter is a non-zero value,
the Config pin will be configured as an output and set low until the first RF packet is received.
With a non-zero RP parameter, the Config pin will be an input for RP ms after power up.
RR (Retries) Command
Networking> RR Command reads/sets the
number of retries that can be sent for a given RF
packet. Once RR Command is enabled (set to a
non-zero value), RF packet acknowledgements
and retries are enabled. After transmitting a
packet, the transmitter will wait to receive an
acknowledgement from a receiver. If the
acknowledgement is not received in the period of
time specified by the RN (Delay Slots) Command,
the transmitter will transmit the original packet again. The packet will be transmitted repeatedly
until an acknowledgement is received or until the packet has been sent RR times.
AT Command: ATRR
Binary Command: 0x18 (24 decimal)
Parameter Range: 0 – 0xFF
Default Parameter Value: 0 (disabled)
Number of bytes returned: 1
Minimum Firmware Version Required: 4.22
Note: For retries to work correctly, all modules in the system must have retries enabled.
