User Manual
Table Of Contents
- 1. Overview
- 2. RF Module Operation
- 3. XBee ZigBee Networks
- Introduction to ZigBee
- ZigBee Stack Layers
- Networking Concepts
- ZigBee Application Layers: In Depth
- Coordinator Operation
- Router Operation
- End Device Operation
- Channel Scanning
- 4. Transmission, Addressing, and Routing
- 5. Security
- 6. Network Commissioning and Diagnostics
- 7. Managing End Devices
- 8. XBee Analog and Digital IO Lines
- 9. API Operation
- API Frame Specifications
- API UART Exchanges
- Supporting the API
- API Frames
- AT Command
- AT Command - Queue Parameter Value
- ZigBee Transmit Request
- Explicit Addressing ZigBee Command Frame
- Remote AT Command Request
- Create Source Route
- AT Command Response
- Modem Status
- ZigBee Transmit Status
- ZigBee Receive Packet
- ZigBee Explicit Rx Indicator
- ZigBee IO Data Sample Rx Indicator
- XBee Sensor Read Indicator
- Node Identification Indicator
- Remote Command Response
- Over-the-Air Firmware Update Status
- Route Record Indicator
- Many-to-One Route Request Indicator
- Sending ZigBee Device Objects (ZDO) Commands with the API
- Sending ZigBee Cluster Library (ZCL) Commands with the API
- Sending Public Profile Commands with the API
- 10. XBee Command Reference Tables
- 11. Module Support
- Appendix A: Definitions
- Appendix B: Agency Certifications
- Appendix C: Migrating from ZNet 2.5 to XBee ZB
- Appendix D: Additional Information
©2011DigiInternational,Inc. 98
9.APIOperation
As an alternative to Transparent Operation, API (Application Programming Interface) Operations are available. API
operation requires that communication with the module be done through a structured interface (data is communicated in
frames in a defined order). The API specifies how commands, command responses and module status messages are sent
and received from the module using a UART Data Frame.
Please note that Digi may add new API frames to future versions of firmware, so please build into your software interface
the ability to filter out additional API frames with unknown Frame Types.
API Frame Specifications
Two API modes are supported and both can be enabled using the AP (API Enable) command. Use the following AP
parameter values to configure the module to operate in a particular mode:
•AP = 1: API Operation
•AP = 2: API Operation (with escaped characters)
API Operation (AP parameter = 1)
When this API mode is enabled (AP = 1), the UART data frame structure is defined as follows:
UARTDataFrameStructure:
MSB=MostSignificantByte,LSB=Lea st SignificantByte
Any data received prior to the start delimiter is silently discarded. If the frame is not received correctly or if
the checksum fails, the module will reply with a module status frame indicating the nature of the failure.
API Operation - with Escape Characters (AP parameter = 2)
When this API mode is enabled (AP = 2), the UART data frame structure is defined as follows:
UARTDataFrameStructure‐withescapecontrolcharacters:
MSB=MostSignificantByte,LSB=Lea st SignificantByte
Escape characters. When sending or receiving a UART data frame, specific data values must be escaped
(flagged) so they do not interfere with the data frame sequencing. To escape an interfering data byte,
insert 0x7D and follow it with the byte to be escaped XOR’d with 0x20.
Length
(Bytes 2-3)
Checksum
(Byte n + 1)
MSB LSB 1 Byte
Start Delimiter
(Byte 1)
0x7E
Frame Data
(Bytes 4-n)
API-specific Structure
Start Delimiter
(Byte 1)
Length
(Bytes 2-3)
Frame Data
(Bytes 4-n)
Checksum
(Byte n + 1)
0x7E MSB LSB API-specific Structure 1 Byte
Characters Escaped If Needed