MRX-900 900 MHz Spread-Spectrum Wireless Modem Operating Manual Microhard Systems Inc.
MRX-900 900 MHz Spread-Spectrum Wireless Modem This manual contains information of proprietary interest to Microhard Systems Inc. It has been supplied in confidence to purchasers and users of the MRX-900, 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. Introduction 1.0 Product Overview ....................................................................................................................................... 1 1.1 Features....................................................................................................................................................... 1 1.2 About this Manual.......................................................................................................................................
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1. Introduction 1.0 Product Overview Congratulations on choosing the MRX-900 wireless modem! Your new MRX-900 is a state-of-the-art, 900 MHz frequency-hopping spread-spectrum communications transceiver. Equipped with the MRX-900, terminal devices (DTEs) up to 30 km (or more)1 apart will be capable of establishing highspeed2 communications wirelessly.
n twenty different user-selectable pseudo-random hopping patterns 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 MRX-900 can be used as a drop-in replacement for most null-m
2. Initial Setup and Configuration 2.0 Unpacking and Inspection The following items should be found in the shipping carton. Inspect the modem and accessories for 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.
2.2 Connectors and Indicators Locate the rear panel of the MRX-900. The interface connectors and indicator lights are summarized below. This manual will refer to these items in the sections that follow. 9 VDC Input - It is recommended that the provided power adapter be used to supply power to the MRX-900 via this connector, although any compatible DC power source which has an output of 9 volts and at least 1 amp may be used.
2.4 Configuration Prior to establishing a wireless link, each MRX-900 that will participate in the link must be correctly configured for compatibility and for the desired mode of operation. The two most common types of networks used are: n Point-to-point: A master station communicates with a single slave station. n Point-to-multipoint: A master station communications with two or more slave stations. Within any network, the master will communicate only with slave(s) assigned to the same network.
n The Wireless Link Rate for both modems must be the same. n The Network Address assigned for both modems must be the same. n The Unit Address assigned for both modems must be the same. n The same Hopping Pattern must be selected for both modems. n Both modems must use the same Encryption Key. B.
3. Configuration Options 3.0 Configuration Parameters The MRX-900 is easily configured to meet a wide range of needs and applications. Configuration is fully menu-driven and requires only a terminal with a 9600 baud RS-232 port. Configuration mode is initiated by depressing the Configuration Button on the back panel of the MRX-900 and holding it for at least two or three seconds.
Operating Mode * 1) Master - Point to Point 2) Slave - Point to Point 3) Master - Point to Multipoint 4) Slave - Point to Multipoint 5) Repeater ESC to exit Select Operating Mode : _ Each unit must be either a Master, Slave, or Repeater. Only one Master can exist for each network. Each unit should be configured as a Master or Slave, except when it is used as a Repeater.
3.2 Serial Baud Rate The Serial Baud Rate is the speed that the DTE communications port will be set at during normal operation. This rate has no bearing on the serial rate during configuration, which is always performed at 9600 baud.
3.4 Network Address Select a Network Address and assign it to all units which will be included in the network. The Network Address defines the membership 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 using the same hardware. As well, the Network Address provides a measure of privacy and security.
3.7 Encryption Key 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. By selecting option 7 from the configuration menu, you are prompted to enter a key (valid values range from 0 to 65535), followed by Return or Enter: Encryption Key = 6109 ESC to exit Set Encryption Key : _ Keep in mind that all units within the network must use the same key for communications to succeed. 3.
3.9 Packet Parameters Packet Parameters define the characteristics of the internal packets or frames which are transmitted. The settings should be set only by an expert since adequate care must be taken to maintain reliability and optimum performance. .
3.10 Radio Statistics This option (selection A) displays a list of performance statistics for the unit since it was powered up. Note that this information is only available if configuration is not initiated immediately after a power-up cycle; loss of power will reset the statistics.
1) Add Slave Selecting this option subsequently prompts for a slave address: “Add Slave Address : _“. Enter a value from 0 to 65535 which corresponds to a Slave Unit Address, followed by Enter/Return. Use care to ensure the value is correctly entered since there is no way for the Master or Repeater to validate the entry. Up to 255 Slaves may be added to the Slave List. 2) Delete Slave This operation is used to reverse the action of option 1, removing a previously-entered slave from the Slave List.
(1) 1) Master - Point to Point 2) Slave - Point to Point 3) Master - Point to Multipoint 4) Slave - Pont to Multipoint 5) Repeater Operating Mode (2) 1) 115200 2) 57600 3) 38400 4) 28800 5) 19200 6) 14400 7) 9600 8) 7200 9) 4800 A) 3600 B) 2400 Serial Baud Rate (3) 1) Turbo 2) Fast 3) Normal Wireless Link Rate (4) 0-65535 Unit Address (5) (1) MRX-900 Operating Manual: The Configuration Menus Maximum Size (2) 0-65535 A-T (7) Encryption Key Hopping Pattern (6) Configuration Main Menu (8)
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B. Configuration Record The following tables are provided as a convenient way to record the configuration of your MRX-900s for future reference. You may wish to copy or adapt it for your use.
o Point-to-Multipoint Operation Unit Mode Master Address Slave List: S/N: _________ Slave S/N: _________ Slave S/N: _________ Slave S/N: _________ Slave S/N: _________ Slave S/N: _________ Slave S/N: _________ Repeater Unique o 1 mW Unit Address o 10 mW (0-65535): o 100 mW o 1000 mW (1W) Unique o 1 mW Unit Address o 10 mW (0-65535): o 100 mW o 1000 mW (1W) Unique o 1 mW Unit Address o 10 mW (0-65535): o 100 mW o 1000 mW (1W) Unique o 1 mW Unit Address o 10 mW (0-65535): o 100 mW o 1000 mW (1W)
C. RS-232 Interface and Cables C.0 RS-232 Line Signals The MRX-900 uses a 9-pin D-sub connector for asynchronous serial I/O. The pin assignments conform to standard RS-232 signals, so a common serial cable can be used for interfacing the MRX-900 to most DTE devices.
“Crossover” / “Null” DB9-to-DB9 RS-232 Cable 9-pin 9-pin 1,6 4 2 3 3 2 4 1,6 5 5 7 8 8 7 9 (n/c) (n/c) 9 “Crossover” / “Null” DB9-to-DB25 RS-232 Cable 9-pin 25-pin 1,6 20 2 2 3 3 4 6,8 5 7 7 5 8 4 9 (n/c) (n/c) 9 “Crossover” / “Null” DB25-to-DB25 RS-232 Cable 25-pin 1 2 3 4 5 6,8 7 20 25-pin 1 3 2 5 4 2
D. Surface or Wall Mounting The drill template and dimensional figure below has been provided to facilitate placement in case you wish to mount your MRX-900. Make a copy of the template at 100% scale and drill through the paper at each of the cross-hairs. Screw heads should be no larger than 5/16” diameter, with outer screw shaft of no more than about 1/8”.
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E. Troubleshooting Here are solutions to some of the common problems and symptoms that may be experienced. ———————————— Problem: I am trying to set up the MRX-900 but I cannot get the configuration menu to appear. Solutions: 1. Make sure you are depressing the Configuration Button for at least 2 or 3 seconds. The Configuration Menu, by design, only shows up after the button has been held briefly to prevent unintentional triggering. 2.
2. If you are using an MRX-900 as a Repeater, it will cut the effective throughput roughly in half because of its “store and forward” nature; the repeater spends half of its time receiving data and the other half transmitting the received data. 3. Although some high speed rates are achieved under ideal conditions, various factors may reduce the effective speed. This includes external RF (radio frequency) interference from sources such as cellular telephones and base stations.
F. Technical Specifications Electrical/Physical Data Interface Asynchronous RS-232, 9-pin female D-sub Signals Data Rate Sig. Gnd, TX, RX, DCD, DSR, DTR, RTS, CTS 2,400 - 115,200 bps, uncompressed half-duplex, Communications Range1 30 kilometers or more Power Requirements 9.0 VDC, 1.
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G. Glossary Terminology Used in the MRX-900 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.
using flow-control and handshaking signals, but 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.