™ MRF450 User Manual U077.0.2-MRF450 2014 Cervis, Inc.
Module RF450 This document is the property of Cervis, Inc. and cannot be copied, modified, e-mailed, or reproduced without the express prior written consent of Cervis, Inc. Cervis, Inc. reserves the right to change this manual or edit, delete, or modify any information without prior notification. Operation of this module in Periodic Transmit mode requires a license. FCC Statements 15.19 – Two Part Warning This device complies with Part 15 of the FCC rules.
User Manual Table of Contents Table of Contents .......................................................................................................................... i List of Figures ............................................................................................................................... i List of Tables ................................................................................................................................. i Cervis Inc. Safety Precautions ..............
Module RF450 Table 9. Receive Message Structure ......................................................................................... 13 Table 10. Error Message Structure ............................................................................................ 14 ii U077.0.
User Manual Notes and Observations 2014 Cervis, Inc.
User Manual Cervis Inc. Safety Precautions Read and follow all instructions. Failure to abide by Safety Precautions may result in equipment failure, loss of authority to operate the equipment, and personal injury. Use and maintain proper wiring. Follow equipment manufacturer instructions. Improper, loose, and frayed wiring can cause system failure, equipment damage, and intermittent operation.
Module RF450 1.0 Introduction The MRF450 radio module is an RF modem. The module consists of a Silicon Labs RF transceiver coupled with a 32-bit Atmel ARM processor. The module is intended to be integrated into Cervis product, providing RF connectivity while hiding the complexity of RF communications and link management. The radio is designed to operate in the 450 – 470 MHz band with a maximum output power of less than 15 dBm.
User Manual 1.2 Dimensions (mils)/Locations Figure 2. Dimensions (mils)/Locations 1.3 Pinout Table 1. P1, P2, and P3 Pinout P1 Pin Assignment I/0 P3 Pin Assignment I/0 P1.1 +VDC 3.3V P1.1 +VDC 3.3V P1.2 -VDC GND P1.2 TMS IN P1.3 Enable IN, High P1.3 -VDC GND P1.4 OC Flag OUT, Low P1.4 TCK IN P1.5 SPI SCK IN P1.5 -VDC GND P1.6 SPI SDI / UART RX IN P1.6 TDO OUT P1.7 SPI SDO / UART TX OUT P1.7 NC NC P1.8 SPI nSS IN, Low P1.8 TDI IN P1.9 F0 IN/OUT P1.
Module RF450 2.0 Installation When integrating this module into a host, the user must provide all text in the “FCC Statements” and “Industry Canada Statements” into the host device’s user manual (see Forward Material). The text must not be modified in any way and presented in a conspicuous manner that the end user can be reasonably expected to access. The module is provided with an RF adapter cable and antenna. The RF adapter cable converts MCX to RP-TNC plug.
User Manual 4.0 Electrical Characteristics 4.1 Power The module requires a regulated 3.3 VDC source. The module does not provide under-voltage, over-voltage, or reverse polarity protection so use caution when applying power. The module transitions between states during normal operation. The integrated PA consumes the largest amount of power when active. Therefore, transitions to the transmit state will cause the largest draw on the host supply.
Module RF450 Table 2. Recommended Baud Rates and Associated Deviation Requested Baud Generated Baud % Error 9600 9615 0.16 14400 14493 0.64 19200 19231 0.16 38400 38462 0.16 57600 58824 2.08 115200 111111 3.68 200000 200000 0 250000 250000 0 333333 333333 0 500000 500000 0 1000000 1000000 0 8000000 8000000 0 The following formulae are used to calculate the baud rate: 8,000,000 16 Divisor is a 16-bit integer value so be sure to round the result.
User Manual 6.0 Operational Modes The module can be configured to operate in one of two modes; Push-To-Transmit mode and Periodic mode. These modes are discussed in this section. Refer to section “8.1 Get / Set Parameter” for instructions on changing the operational mode. 6.1 Push-To-Transmit Mode Push-To-Transmit is the module’s default mode. Any time power is applied to the module it will begin operation in this mode.
Module RF450 7.0 Communication Protocol Communication between the module and host is packetized. Each packet begins with a start-ofpacket (SOP) indicator, followed by the length of the packet message, followed by the message, and terminated with a checksum calculated over the message. All multi-byte fields are interpreted in little-endian format; the LSB is stored in the lowest address and the MSB is stored in the highest. A diagram of the packet format follows. Table 4.
User Manual The inter-byte timer is set to 10 byte-times. At 115200 baud this is 868 µs. The last-byte timer is set to 25 byte-times. At 115200 baud this is 2170 µs. 7.3 Acknowledgement Every packet sent to the module will result in a response packet sent back to the host. In addition, the module will generate a message to the host when an RF packet is received and destined for the host. In UART mode the packet will be sent asynchronously.
Module RF450 8.0 Messages The heart of the communication packet structure is the message field. This field carries the specific information of the packet. The first byte of the message field is interpreted as the message ID. The remaining bytes in the message are interpreted based on the message ID. The message IDs and structures follow. Table 5. Message IDs and Structures 0 .. ID ID-Dependent n Message Field 8.1 Get / Set Parameter This group of messages is used to set and read module parameters.
User Manual ID Parameter Bytes Default Mode Description 0x01 = RX. Fastest response. ~10 mA more than Idle. 0x0030 RX Filter Options 1 0x00 Binary-encoded options. 1 If set, filter DST PAN against My PAN 2 If set, filter DST Address against My Address 4 If set, strip DST PAN from payload 5 If set, strip DST Address from payload 6 If set, strip SRC PAN from payload 7 If set, strip SRC Address from payload If enabled, filter fields must match or the packet is silently discarded.
Module RF450 8.2 Transmit This message instructs the module to transmit a packet. The message contains an options field followed by the payload to be sent. The maximum payload is 63 bytes. The maximum payload is further reduced by 2 bytes for each addressing field automatically appended. If all addressing fields are appended by the module (Options = 0xFX) the maximum payload is 63 – (2 * 4) = 55. Table 8. Transmit ID, Reply Transmit ID = 0x10, Reply = 0xA0. 0 1 ID Options 2 ..
User Manual 8.3 Receive This message instructs the module to enter receive mode for the specified time in milliseconds. The module will dwell in the receive state until a packet is received or the timeout expires. At this time the module will return to the state specified in the Default Mode parameter. If a transmit command is issued while this command is active it will clear the receive timer and terminate the current receive operation.
Module RF450 8.4 Error This message is sent by the module back to the host to indicate unexpected operation. Table 10. Error Message Structure Error ID = 0xFF 0 1 ID Error 0xFF The Error field is an enumerated type with the following definitions: Error Name 0 No Error No Error 1 No SOP SOP is missing 2 Length 3 CRC 4 Bad ID 5 Bad Parameter 14 Description Length of message exceeds maximum CRC mismatch Unsupported message ID Unsupported parameter address U077.0.
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