Product manual
XStream‐PKG‐R™RS‐232/485RFModem–ProductManualv4.2B
©2005MaxStream,Inc.Confidential&Proprietary 30
RP (RSSI PWM Timer) Command
<Diagnostics> RP Command is used to enable a
PWM (“Pulse Width Modulation”) output on the
Config pin which is calibrated to show the level
the received RF signal is above the sensitivity
level of the 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 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 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
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 specifies 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 modems in the system must have retries enabled.
RS (RSSI) Command
<Diagnostics> RS Command returns the signal
level of the last packet received. This reading is
useful for determining range characteristics of the
XStream Modems under various conditions of
noise and distance.
Once the command is issued, the modem will
return a value between 0x6 and 0x36 where
0x36 represents a very strong signal level and 0x4 indicates a low signal level.
AT Command: ATRS
Binary Command: 0x1C (28 decimal)
Parameter Range: 0x06 – 0x36 [Read-only]
Number of bytes returned: 1
Minimum Firmware Version Required: 4.22