Operating Manual And Professional Installation Guide TM CompactRF OEM Spread Spectrum Transceiver Revision 1.00, Sept 15, 2000 Microhard Systems Inc. #110, 1144 - 29th Ave. N.E. Calgary, Alberta T2E 7P1 Phone: (403) 248-0028 Fax: (403) 248-2762 www.microhardcorp.
TM CompactRF 900 MHz OEM Spread Spectrum Transceiver This manual contains information of proprietary interest to Microhard Systems Inc. It has been supplied in confidence to purchasers and users of the CompactRF, and by accepting this material the recipient agrees that the contents will not be copied or reproduced, in whole or in part, without prior written consent of Microhard Systems Inc. Microhard Systems Inc. has made every effort to assure that this document is accurate and complete.
Contents 1. 2. 3. 4. 5. A. B. C. D ..... F. G. H. I. iii Introduction 1.0 Product Overview .............................................................................................................................................................................. 1 1.1 Features.............................................................................................................................................................................................. 1 1.2 About this Manual ..........
iv CompactRF TM Operating Manual
1. Introduction 1.0 Product Overview The CompactRFTM is a high-performance embedded wireless data transceiver. Operating in the 902-928 MHz ISM band, this frequencyhopping spread-spectrum module is capable of providing reliable wireless data transfer between almost any type of equipment which uses an asynchronous serial interface. The small-size and low operating current of this module make it ideal for mobile and battery powered applications.
n 30 sets of user-selectable pseudo-random hopping patterns, intelligently designed to offer the possibility of separately operating multiple networks while providing security, reliability and high tolerance to interference; n encryption key with 65536 user-selectable values to maximize security and privacy of communications; n built-in CRC-16 error detection and auto re-transmit to provide 100% accuracy and reliability of data; n ease of installation and use – the CompactRFTM gives the user the choice of a
1.3 Unpacking and Inspection The following items should be found in the shipping carton. Inspect the contents for any shipping damage. Report damages or shortages to the distributor from which the unit was purchased. Keep all packing materials in the event that transportation is required in the future.
4 CompactRF TM Operating Manual: Chapter 1 Introduction
2. Electrical/Physical 2.0 Functional Block Diagram DVcc ARSSI AVcc Mixer LNA Antenna Switch IF Demod GND - + Frequency Synthesizer Comparator Mixer PA GAIN \Config \Reset \Sleep RSSI1-3 SYNC RXMODE TXMODE uC A/D SRAM EEPROM 8 bit data bus TxD RTS DTR CompactRF TM Operating Manual: Chapter 2 Electrical/Physical UART (DCE) RxD CTS DSR DCD 5
2.1 Pinout Figure 1 provides a top-view pinout drawing of the CompactRF module. The corner pins (1,18,19,36) are labeled directly on the module. NC NC NC NC \Config SYNC RSSI1 RSSI2 RSSI3 Rx Mode Tx Mode PGM GND GND GND GND GND AVcc 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 T M CompactRF 900MHz 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 AVcc GND ARSSI NC NC \Reset DVcc GND TxD RxD GND DSR CTS DCD RTS DTR SCK \Sleep Figure 1 - Pinout (Top View) 6 Pin Name No.
CompactRF TM Pin Name No. Description I/O DTR 21 RS-232 Data Terminal Ready. Active low (TTL level) input. I DVcc 30 Positive Supply for Logic circuitry and I/O pins. See Section 2.2 for DC Characteristics GND 13-17 26,29, 35 Ground reference for logic, radio and I/O pins. PGM 12 Programming Status indicator. This output is for factory use only, and should normally be left disconnected. O \Reset 31 Active low reset input to the module. See Section 2.3 for timing information.
For detailed mechanical drawings, refer to Appendix H 2.2 DC Characteristics Sym Characteristic Min Typ Max Units AVCC Radio Supply Voltage 4.9 5.0 5.5 V DVCC Logic Supply Voltage 4.75 5.0 5.5 V VPOT Power On Reset Threshold Voltage 1.8 2 2.
2.3 AC Characteristics Sym Characteristic Min Typ Max Units TTOUT Reset Delay Time-Out Period 12.8 16.0 19.2 ms TCFG \Config. pulse duration TS2SD \Sleep low to internal sleep delay TSN Snooze duration 10 ms TSNIFF Sniff duration 100 us TWDLY \Sleep high to internal wakeup See Note ms 0 0 See Note TSN ms ms Note: The minimum duration for TCFG is one hop interval. The hop interval is set by the user, and is stored in register S109.
10 CompactRF TM Operating Manual: Chapter 2 Electrical/Physical
3. Modes of Operation The CompactRFTM modem can be easily configured to meet a wide range of needs and applications. The module is designed such that all communication is through one serial port (Pins 21 to 28 on the module). This port has two functions: 1. It provides the asynchronous interface with the host equipment for data that is sent/received on the RF channel. When operating in this fashion, the module is said to be in data mode. 2. It is also used for configuring and programming the module.
When configured as a Slave, the CompactRF searches for synchronization with a Master. Network topologies consisting of a single Master and virtually any combination of Slaves and Repeaters may be deployed. The functionality of any particular CompactRFTM can be configured as follows: S M Network 1 R M n Master Point-to-Point: The modem is configured to communicate with a single Slave, either directly, or through one or more Repeaters.
3.2.1 Menu Interface At this point, you should see a menu similar to the following appear: Microhard Systems Inc CompactRF Configuration 1) Operating Mode S101=1 MasterPP 2) Serial Baud Rate S102=4 9600 3) Network Address S104=255 4) Unit Address S105=65535 5) Hopping Pattern S106=0 6) Encryption Key S107=65535 7) Output Power Level S108=0 1 mW 8) Retry Limit S213=255 9) Hop Interval S109=20 x 0.
When using AT Commands, use the &W command to store the most current settings to memory. With AT Commands, the settings are not immediately stored to non-volatile memory, therefore if the modem is powered down at this point, the Operating Mode would revert to its previous value. To store any recently updated command registers, the following “write” command must be entered. AT&W 3.
The modem will now attempt to communicate with other CompactRF modules. While in Data Mode, the modem will communicate through the serial port at the same baud rate as was last used in Command Mode2. To return to Command Mode, you can either: The escape sequence will not be accepted unless both the CompactRFTM and the terminal are set to the same baud rate • Send the escape sequence.
16 CompactRF TM Operating Manual: Chapter 3 Modes of Operation
4. Configuration This chapter provides a detailed description of the various operating parameters of the CompactRF. Section 4.1 provides a quick-start approach which outlines the minimum requirements for establishing communication between two CompactRF modules. The settings will not necessarily provide optimal performance for your application, but will verify that the modules are functioning correctly. Section 4.2 describes the AT Command interface. Section 4.
The units should now be communicating. Remember, the parameters defined by Factory Settings 1 and 2 will likely not be the most ideal for your application, but will quickly allow you to test the units. A complete summary of the settings defined by all four factory settings can be found in Appendix C. Factory Default Settings. Settings are not immediately stored in non-volatile memory when using AT Commands, therefore, the command &W is issued to store the current configuration into non-volatile memory.
Note that the terminal must be configured to the same baud rate as the modem in order for the modem to recognize the escape sequence. The modem is unable to “autobaud” while in Data Mode. The following is a description of all available commands. ‘*’ denotes standard factory settings. All of the following commands must be preceded by “AT”. A Answer The A command causes the modem to attempt to connect with another remote modem (Type ATA ).
&V View Configuration The &V command displays all S registers and their current values. &E Framing Error Check NOT YET IMPLEMENTED This command enables or disables Framing Error Check. When enabled, the modem looks for the stop bit. If the stop bit is absent, the byte is thrown out. When enabled, the modem also does a parity check. Note that the data format (number of data bits, parity type, and number of stop bits) is defined by S register 110.
4.3 AT Registers The parameters described in this section apply to AT Command operation only. S Register 0 - Auto Answer If this register is set to zero, the modem will power up in command mode. If this register is non-zero, the modem will power up in data mode. S Registers 2 through 5 cannot be stored to nonvolatile memory. S Register 2 - Escape Code This register contains the ASCII value of the escape character. The default value (decimal 43) is equivalent to the ASCII character ‘+’.
4.4 Configuration Settings The parameters described in this section affect the operating characteristics of the CompactRF module. All the settings described in this section can be configured using either the AT Command interface or the menu interface. DCD (Data Carrier Detect) AT Menu &C M The &C command controls the modem’s DCD output signal to the host microprocessor. This command determines when the DCD is active. &C0 *&C1 &C2 DCD is always ON DCD on when modems are synchronized.
Handshaking AT Menu &K A This command controls the handshaking between the modem and host microprocessor. &K0 &K2 *&K3 Disable handshaking RTS/CTS input data framing. See page 33 for details. Enable hardware handshaking (RTS/CTS) DSR (Data Set Ready) AT Menu &S O This command controls the DSR line for the modem, and determines when it is active &S0 *&S1 DSR is always ON DSR is ON in Data Mode, OFF in Command Mode Operating Mode Only one Master can exist for each network.
2)Master - Point to Point. This mode of operation is identical to Master Point-to-Multipoint, with the exception that the Master only broadcasts to one particular Slave or Repeater. The modem with which communication occurs is defined by the Unit Address (S105). For example, if a Slave has been assigned Unit Address 100, and the Master wishes to communicate with that Slave, the Master must also be assigned a Unit Address of 100.
Serial Baud Rate AT Menu S101 1 The Serial Baud Rate is the current speed that the modem is using to communicate with the DTE. When the AT command prefix is issued, the modem performs an ‘autobaud’ operation and determines what the current DTE baud rate is set to. The S register value returns the current setting of the DTE baud rate.
Select a Network Address and assign it to all units which will be included in the network. Network Address AT Menu S104 3 The Network Address defines the communications network to which individual units can be a part of. By establishing a network under a common Network Address, the network can be isolated from any other concurrently operating network. As well, the Network Address provides a measure of privacy and security.
the following diagrams illustrate the methodology for deploying simple to complicated networks: Master Slave Master Repeater Master Repeater1 M[1] ←→ S1[1] M[1] ←→ R1[1,2] ←→ S2[2] M[1] ←→ R1[1,2] ←→ R2[2,3] ←→ S3[3] M[1] ←→ R1[1,2] ←→ R2[2,3] ←→ R3[3,4] ←→ S4[4] Slave Repeater2 Slave It is reasonable to consider a Repeater as being both a Slave and a Master, alternating between Primary and Secondary Hopping Patterns as the unit changes channel.
All units within a network must use the same encryption key. Encryption Key AT Menu S107 6 The Encryption Key provides a measure of security and privacy of communications by rendering the transmitted data useless without the correct key on the receiver. Valid Encryption Keys range from 0 to 65535. Keep in mind that all units within the network must use the same key for communications to succeed.
IMPORTANT: FCC Regulations FCC Regulations allow up to 36 dBi effective radiated power (ERP). Therefore, the sum of the transmitted power (in dBm), the cabling loss and the antenna gain cannot exceed 36 dBi. 1 mW = 0 dBm 10 mW = 10 dBm 100 mW = 20 dBm 1000 mW = 30 dBm For example, when transmitting 1 Watt (30 dBm), with cabling losses of 2 dB, the antenna gain cannot exceed 36 - 30 + 2 = 8 dBi. If an antenna with a gain higher than 8 dBi were to be used, the power setting must be adjusted appropriately.
AT Menu Packet Minimum Size S111 G Packet Maximum Size S112 H Packet Character Timeout S116 I These settings determine the conditions under which the modem will transmit accumulated data over the air. S Register 111 - Minimum Size The Minimum and Maximum Packet Size is controlled by the Master. The Slave and Repeater units will use the Minimum and Maximum Packet Size setting from the Master.
Packet Retransmissions AT Menu S113 J This register applies to both Master and Repeater operation. It does not apply to Slave operation. The Master will retransmit each data packet exactly the number of times defined by the Packet Retransmissions parameter. The Master retransmits once at the beginning of each hopping interval until the limit is reached. This parameter is not necessary in Slave units since all Slaves receive acknowledgement from the Master.
Packet Repeat Interval AT Menu S115 L A parameter that is specific to Slaves and Repeaters is the Packet Repeat Interval. The allowable settings are 1 through 255. The default is 1. This parameter defines a range of random numbers that the Slave will use as the next slot in which it will attempt to send the packet. For example, if this register is set to 7, the Slave will choose a number between one and seven as the next slot in which to transmit.
AT Menu RTS/DCD Framing 120 R DCD Timeout 121 S The CompactRFTM supports two special types of data framing: • • Input (or RTS/CTS) Data Framing; and, Output (or DCD) Data Framing Input Data Framing is enabled by configuring the Handshaking Parameter as &K2. This type of framing makes use of the S120 parameter as illustrated in Figure 9. Parameter S120 can be set to any value between 0 and 254 ms.
34 CompactRF TM Operating Manual: Chapter4 Configuration
5. Installation The installation, removal or maintenance of all antenna components must be carried out by qualified and experienced professionals. The installation, removal or maintenance of all antenna components must be carried out by qualified and experienced professionals. The CompactRF complies with FCC part 15 at the modular level for operation in the license-free 902-928 MHz ISM band. This chapter provides guidelines for installing and deploying equipment which incorporates the CompactRF module. 5.
Base Height (m) Mobile Height (m) Distance (km) When deploying your system, care must be taken to ensure the path loss (reduction of signal strength from transmitter to receiver in dB) between equipment does not exceed the system gain (138 dB in the above example). It is recommended to design for a gain margin of at least 10 dB to ensure reliable communication. Gain margin is the difference between system gain and path loss.
5.2 Antennas and Cabling This section describes the recommended procedure for installing cabling and antennas for use with the CompactRF module. 5.2.1 Internal Cabling The most common method for installing the module is to run a cable from the module’s SMA connector to an N-male bulkhead connector on the chassis of the equipment as shown in Figure 11 N-male connector LMR195 Cable with SMA male connector and N-male bulkhead connector SMA male connector Figure 11.
5.2.2 Installing External Cables, Antennas and Lightning Arrestors The installation, removal or maintenance of all antenna components must be carried out by qualified and experienced professionals. The installation, removal or maintenance of all antenna components must be carried out by qualified and experienced professionals. Never work on an antenna system when there is lightning in the area. Direct human contact with the antenna is potentially unhealthy when the CompactRF is generating RF energy.
Antenna Before choosing an antenna, you should have some knowledge of the path loss and the topology of the equipment. If the equipment is in a fixed location and is to communicate with only one other unit also in a fixed location, then a Yagi antenna is suitable. Choose a Yagi with enough gain to ensure adequate gain margin. When deploying the Yagi, point the antenna towards the intended target, ensuring the antenna elements are perpendicular to the ground.
40 CompactRF TM Operating Manual: Chapter 5 Installation
A. Modem Command Summary The following provides a command summary for the CompactRFTM. Factory settings are denoted with a ‘*’.
42 CompactRF TM Operating Manual: Appendix A Modem Command Summary
B. Serial Interface The CompactRFTM uses 8 pins on its 36 pin header for asynchronous serial I/O. The interface conforms to standard RS-232. The signals in the asynchronous serial interface are described below: DCD Data Carrier Detect - Output from Module - When asserted (positive voltage), DCD informs the DTE that a communications link has been TM established with another CompactRF .
44 CompactRF TM Operating Manual: Appendix B Serial Interface
C.
46 CompactRF TM Operating Manual: Appendix C Factory Default Settings
D. Performance Tables The scope of this appendix is to find the best possible performance and maximum packet size at different modes of operation. The setup assumes a baud rate of 115k, no retries and no retransmissions.. Master to Slave Communication. (No Repeater) Link Rate = Fast NO FEC Master to Slave Communication. (No Repeater) Link Rate = Fast WITH FEC Master to Repeater Direct Communication. Link Rate = Fast NO FEC Master to Repeater Direct Communication.
48 CompactRF TM Operating Manual: Appendix D.
50 CompactRF TM Operating Manual:
F. Technical Specifications Electrical/Physical Data Interface Asynchronous Serial Port, TTL Levels Signals Sig. Gnd, TX, RX, DCD, DSR, DTR, RTS, CTS Baud rate 2,400 - 19200 bps, (user-selectable) Up to 19200 full-duplex sustained throughput Communications Range1 16 kilometres (10 miles) Voltage Requirements 4.75 to 5.5 VDC, 1.0 Amp Current Consumption Rx: 85mA; Tx 1mW: 100mA; Tx 10mW: 132mA; Tx 100mW: 231mA; Tx 1W: 600mA; Sleep: <1.
52 CompactRF TM Operating Manual: Appendix F.
G. Development Board Schematics Schematics begin on next page. CompactRF TM Operating Manual: Appendix G.
54 CompactRF TM Operating Manual: Appendix G.
CompactRF TM Operating Manual: Appendix G.
56 CompactRF TM Operating Manual: Appendix G.
CompactRF TM Operating Manual: Appendix G.
58 CompactRF TM Operating Manual: Appendix H.
H. Mechanical Drawing 1500 375 19 18 75 330 Top View 2000 78.7 (2mm) Pin 1 36 Dimensions in thousandths of an inch. Shaded areas = keep clear. 80 525 dia. 64 410 200 225 Recommended Footprint Drill Size = 32 mil 18 19 78.7 (2mm) 1245 Microhard Systems Inc. Document Number: D1043-02 1 36 1245 500 Sheet 1 of 1 Rev. 2 110, 1144 - 29th Avenue N.E..
60 CompactRF TM Operating Manual: Appendix H.
I. Glossary Terminology Used in the CompactRFTM Operating Manual Asynchronous communications A method of telecommunications in which units of single bytes of data are sent separately and at an arbitrary time (not periodically or referenced to a clock). Bytes are “padded” with start and stop bits to distinguish each as a unit for the receiving end, which need not be synchronized with the sending terminal. Attenuation The loss of signal power through equipment, lines/cables, or other transmission devices.
can be controlled also by software using X-ON/XOFF (transmitter on/off) commands. Frequency-hopping A type of spread spectrum communication whereby the carrier frequency used between transmitter and receiver changes repeatedly in a synchronized fashion according to a specified algorithm or table. This minimizes unauthorized jamming (interference) and interception of telecommunications. Full-duplex Where data can be transmitted, simultaneously and independently, bidirectionally.
