XTH9-MI-128 Digi International/Maxstream, XTH9-MI-128 Datasheet - Page 39

• Manufacturer Part Number: XTH9-MI-128
• Description: MODULE RF 900MHZ 1W 115K W/MMCX
• Manufacturer: Digi International/Maxstream

Specifications of XTH9-MI-128

• Frequency: 900MHz
• Data Rate - Maximum: 230kbps
• Modulation Or Protocol: FHSS, FSK
• Power - Output: 30dBm
• Sensitivity: -110dBm
• Voltage - Supply: 3.3V, 5V
• Current - Receiving: 80mA
• Current - Transmitting: 260mA
• Data Interface: Connector, 2 x 10 Header
• Antenna Connector: MMCX
• Operating Temperature: -40°C ~ 85°C
• Package / Case: Module
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Applications: -
• Memory Size: -

XTend™ RF Module ‐ Product Manual v2.x6x
API Operation
API Frame Specifications
API Operation (AP parameter = 1)
API Operation - with Escape Characters (AP parameter = 2)
By default, XTend RF Modules act as a serial line replacement (Transparent Operation) - all UART
data received through the DI pin is queued up for RF transmission. When the module receives an
RF packet, the data is sent out the DO pin with no additional information.
Inherent to Transparent Operation are the following behaviors:
As an alternative to the default 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 spec-
ifies how commands, command responses and module status messages are sent and received
from the module using a UART data frame.
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:
Any data received prior to the start delimiter is silently discarded. If the frame is not received cor-
rectly or if the checksum fails, the data is silently discarded.
When this API mode is enabled (AP = 1), the UART data frame structure is defined as follows:
Figure 3‐01. UART Data Frame Structure:
When this API mode is enabled (AP = 2), the UART data frame structure is defined as follows:
Figure 3‐02. UART Data Frame Structure ‐ with escape control characters:
Escape characters. When sending or receiving a UART data frame, specific data values must be
escaped (flagged) so they do not interfere with the UART or UART data frame operation. To escape
an interfering data byte, insert 0x7D and follow it with the byte to be escaped XOR’d with 0x20.
© 2010 Digi Internatonal, Inc.
• If module parameter registers are to be set or queried, a special operation is required for
• In point-to-multipoint systems, the application must send extra information so that the
• AP = 0 (default): Transparent Operation (UART Serial line replacement)
• AP = 1: API Operation
• AP = 2: API Operation (with escaped characters)
Start Delimiter
Start Delimiter
transitioning the module into Command Mode [refer to p17].
receiving module(s) can distinguish between data coming from different remotes.
API modes are disabled.
(Byte 1)
(Byte 1)
0x7E
0x7E
MSB = Most Significant Byte, LSB = Least Significant Byte
MSB = Most Significant Byte, LSB = Least Significant Byte
MSB
MSB
(Bytes 2-3)
(Bytes 2-3)
Length
Length
LSB
LSB
Characters Escaped If Needed
API-specific Structure
API-specific Structure
Frame Data
Frame Data
(Bytes 4-n)
(Bytes 4-n)
(Byte n + 1)
(Byte n + 1)
Checksum
Checksum
1 Byte
1 Byte
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