BB-ZP9D115RMLR-A Radio Modem
41
RP (RSSI PWM Timer) Command
<Diagnostics> RP Command is used
to enable a PWM ("Pulse Width
Modulation") output on the
Config/RSSI pin (pin 11 of the OEM
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):
PWM Values
dBm above sensitivity
PWM percentage (high period / total period)
10
20%
20
35%
30
50%
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
powered, 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.
RR (Retries) Command
<Networking & Security> The RR
command is used to set/read the
maximum number of retries sent for a
given RF packet. When RR Command
is enabled (RR>0), RF packet retries
and ACKs (acknowledgements) are
enabled.
Exceptions: If the MT command in enabled (MT>0) or if a broadcast Destination Address is
used (DT = 0xFFFF); RF packet retries and ACKs are disabled.
After transmitting a packet, the transmitting RF module waits to receive an
acknowledgement from a receiving module. If the acknowledgement is not received in the
period of time specified by RN (Delay Slots) Command, the original packet is transmitted
again. The RF packet is transmitted repeatedly until an acknowledgement is received or
until the packet is sent RR times.
AT Command: ATRP
Binary Command: 0x22 (34 decimal)
Parameter Range: 0 - 0xFF [x 100 milliseconds]
Default Parameter Value: 0x20 (32d)
Number of Bytes Returned: 1
AT Command: ATRR
Binary Command: 0x18 (24 decimal)
Parameter Range: 0 - 0xFF
Default Parameter Value: 0x0A (10 decimal)
Number of Bytes Returned: 1
