Dio Pin Change Detect; Sample Rate (Interval); I/O Line Passing - Digi XBee User Manual

Operation

DIO pin change detect

When you use the IC (DIO Change Detect) command to enable DIO Change Detect, DIO lines 0 - 7 are
monitored. When a change is detected on a DIO line, the following occurs:
1. An RF packet is sent with the updated DIO pin levels. This packet does not contain any ADC
samples.
2. Any queued samples are transmitted before the change detect data. This may result in
receiving a packet with less than IT (Samples before TX) samples.
Note Change detect does not affect Pin Sleep wake-up. The D8 pin (DTR/Sleep_RQ/DI8) is the only line
that wakes a device from Pin Sleep. If not all samples are collected, the device still enters Sleep Mode
after a change detect packet is sent. Change detect is only supported when the Dx (DIOx
Configuration) parameter equals 3, 4 or 5.
Applicable Commands: IC (DIO Change Detect), IT (Samples before TX)
Note Change detect is only supported when the Dx (DIOx Configuration) parameter equals 3, 4 or 5.

Sample rate (interval)

The Sample Rate (Interval) feature allows enabled ADC and DIO pins to be read periodically on devices
that are not configured to operate in Sleep Mode. When one of the Sleep Modes is enabled and the
(Sample Rate) parameter is set, the device stays awake until
been collected.
Once a particular pin is enabled, the appropriate sample rate must be chosen. The maximum sample
rate that can be achieved while using one A/D line is 1 sample/ms or 1 kHz. The device cannot keep up
with transmission when IR and IT are equal to 1 and we do not recommend configuring the device to
sample at rates greater than once every 20 ms.

I/O line passing

You can set up virtual wires between XBee/XBee-PRO Modules. When a device receives an RF data
packet that contains I/O data, it can be setup to update any enabled outputs (PWM and DIO) based on
the data it receives.
I/O lines are mapped in pairs. For example, AD0 can only update PWM0 and DI5 can only update DO5.
The default setup is for outputs not to be updated, which results in the I/O data being sent out the
UART (See the IU (I/O Output Enable)
Input Address) parameter with the address of the device that has the appropriate inputs enabled. This
binds the outputs to a particular device's input. This does not affect the ability of the device to receive
I/O line data from other modules; if affects only its ability to update enabled outputs. The IA
parameter can also be set up to accept I/O data for output changes from any module by setting the IA
parameter to 0xFFFF.
When outputs are changed from their non-active state, the device can be setup to return the output
level to its non-active state. Set the timers using the Tn (Dn Output Timer) and PT (PWM Output
Timeout) commands. The timers are reset every time the device receives a valid I/O sample packet
with a matching IA address.
You can adjust the IC (Change Detect) and IR (Sample Rate) parameters to keep the outputs set to
their active output if the system needs more time than the timers can handle.
Note DI8 cannot be used for I/O line passing.
XBee/XBee-PRO S1 802.15.4 (Legacy) User Guide
IT (Samples before TX)
command). To enable the outputs for updating, set the IA (I/O
ADC and Digital I/O line support
samples have
IR
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