XBee®/XBee‐PRO® ZB SMT RF Modules
Pin Command Parameter
Description
Data out default low
4
5
Data out default high
6
RS485 enable low / packet trace interface
RS485 enable high
7
>7
Unsupported
When the pin command parameter is a 0 or a 3, it operates the same on this platform, except that the pin will not be
monitored by I/O sampling if the parameter is 0.
Inputs have three variations:
• floating
• pulled-up
• pulled-down
A floating input is appropriate if the pin is attached to an output that always drives the line. In this case, a pull-up
or pull-down resistor would cause more current to be drawn.
A pulled-up input is useful where there might not always be an external source to drive the pin and it is desirable to
have the line read high in the absence of an external driver.
Likewise, a pulled-down input is useful when there is not always an external source to drive the pin and it is desir-
able to have the line read low in the absence of an external driver.
Two commands are available to configure the input type:
• PR determines whether or not an input is pulled. If the corresponding bit in PR is set, then the signal will be
pulled. If it is clear, then the signal will be floating.
• PD determines the pull direction. It only applies when the corresponding bit in PR is set. The bit in PD should
be set to enable an internal pull-up resistor. It should be cleared to enable an internal pull-down resistor.
I/O Sampling
The XBee ZB modules have the ability to monitor and sample the analog and digital I/O lines. I/O samples can be
read locally or transmitted to a remote device to provide indication of the current I/O line states. API mode must be
enabled on the receiving device in order to send I/O samples out the serial port. If this mode is not enabled, then
remote I/O samples will be discarded
There are three ways to obtain I/O samples, either locally or remotely:
• Queried Sampling
• Periodic Sampling
• Change Detection Sampling.
IO sample data is formatted as shown in the table below
Bytes
Name
Sample Sets
Description
1
Number of sample sets in the packet. (Always set to 1.)
© 2010 Digi International, Inc.
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DCD [ DIGITAL CORE DESIGN ]
