AI1422 Half-Frame Reader User Guide TransCore, Inc.
©2004 TC IP, Ltd. All rights reserved. TRANSCORE is a registered trademark. The trademark is used under license. All other trademarks listed are the property of their respective owners. Contents are subject to change. Printed in the U.S.A. Products covered by this document are protected by one or more of the following U.S. patents 4,739,328; 4,864,158; 4,999,636; and foreign equivalent patents. Other patents pending.
WARNING TO USERS IN THE UNITED STATES FEDERAL COMMUNICATIONS COMMISSION (FCC) RADIO FREQUENCY INTERFERENCE STATEMENT 47 CFR §15.105(a) NOTE: This equipment has been tested and found to comply with the limits for a Class A digital device pursuant to Part 15 of the Federal Communications Commission (FCC) rules. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment.
Contents
Contents 1 Before You Begin Purpose of This Guide. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3 Intended Audience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3 Related Documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3 Guide Topics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AI1422 Half-Frame Reader System User Guide 4 System Test Procedures Required Tools and Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3 Testing Basic Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3 Measuring RF Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5 Measuring System Noise. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contents List of Figures Figure 2-1 Figure 3-1 Figure 3-2 Figure 3-3 Figure 4-1 Figure 4-2 Figure 4-3 Figure 4-4 Figure 4-5 Figure 4-6 Typical Reader System Configuration Front Panel of AI1422 Transponder Interrogator RS–232, DB25 Interface Connector Pin-outs . . . . . . . . . . . . . . . . . . . . . . . . . . . . Customer I/O Interface Pin-outs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Power Source Connections Locations for DC Voltage Adjustment Measuring RF Power . . . .
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1 Before You Begin
Chapter 1 Before You Begin The AI1422 Half-Frame Reader User Guide provides information necessary for interfacing the AI1422 Half-Frame Reader System to a host computer system. Purpose of This Guide This user guide provides information for interfacing the AI1422 Half-Frame Reader System with a host processor system, also called a host computer system. This guide also provides on-site test procedures useful in troubleshooting any problems encountered after installation.
AI1422 Half-Frame Reader System User Guide Discusses the firmware command code that are used to configure the AI1422 Reader for communication with a personal computer or other host computer. Chapter 5 – Firmware Command Codes Chapter 6 – Maintenance and Troubleshooting Provides maintenance procedures and troubleshooting indications that are used to keep the AI1422 Half-Frame Reader System operating.
2 System Overview
Chapter 2 System Overview The AI1422 Half-Frame Reader System is a microprocessor-controlled, single-antenna unit that uses a unique communications protocol to interface with vehicle identification (ID) equipment. System Overview This reader system uses radio frequency (RF) energy to read data from tags. The AI1422 Half-Frame Reader System then decodes the tag ID information, validates the ID code, and transmits tag data directly to a host processor for real-time data processing and use.
AI1422 Half-Frame Reader System User Guide The transponder interrogator is operated in a continuous read mode, and any tag entering its read field has its data automatically read and relayed to the host computer. In many applications this function is implemented by installing the reader on a vehicle with restricted movement, such as a railcar or monorail bus. The tags are imbedded in the roadway at various locations in the vehicle’s path.
3 Interface Connections
Chapter 3 Interface Connections This chapter describes the interface connections and their primary functions. Description of AI1422 Reader System Because the AI1422 Half-Frame Reader System combines a reader and radio frequency (RF) module into a single unit, you must connect the following items to the system: the external DC power, the customer input/output (I/O), the main and auxiliary RS–232 interfaces, and the antenna.
AI1422 Half-Frame Reader System User Guide Figure 3-2 RS–232, DB25 Interface Connector Pin-outs Aux RS–232 Interface The auxiliary RS–232 interface is used as a backup monitoring system to the main RS–232 interface. The auxiliary interface monitors data from the transponder interrogator. The auxiliary RS–232 interface is a standard DB25 plug connector. This port is not wired to receive data and cannot accept commands.
Interface Connections Figure 3-3 Customer I/O Interface Pin-outs The customer I/O interface connector contains the lock light-emitting diode (LED), main power LED, RF power LED, the trigger signals, and channels A, B, and C. Lock LED The transistor-transistor-logic (TTL) lock signal shows the presence of a tag. The lock signal goes active high when a valid tag is in the RF field of the antenna and may be connected to an LED for monitoring purposes.
AI1422 Half-Frame Reader System User Guide Channels A, B, and C The analog intermediate frequency channel A, B, and C signals represent the three channels generated by the AI1422 Reader System. These channels can be used to measure tag signal quality. Power Connection The power connector on the front panel of the AI1422 Half-Frame Reader System is a panel mount circular connector of type Cannon CA 3100 E16-10P-F80-T12.
4 System Test Procedures
Chapter 4 System Test Procedures This chapter provides testing procedures that will help you fine-tune your reader system and test basic operation, measure radio frequency (RF) power, measure system noise, read tags, and monitor the system.
AI1422 Half-Frame Reader System User Guide 5. Connect a power source to pins A (+) and B (-) on the DC power input front panel connector (Figure 4-1). Figure 4-1 Power Source Connections 6. Switch on the ON/OFF switch located on the front panel of the reader system. 7. Type the command ~~CC (CC must be entered in upper case) and press Enter. Note: For information on entering command codes, refer to Chapter 5, Command Codes. 8. Type !22 and press Enter. The time and date will be returned.
System Test Procedures Figure 4-2 Locations for DC Voltage Adjustment Measuring RF Power Measuring RF Power To measure the RF power 1. Set the ON/OFF switch located on the front panel of the reader system to off. 2. Connect an RF power meter of known accuracy to the antenna interface on the front panel of the reader system (Figure 4-3). Power measured at the antenna connector should be 0.8 W (29 dBm).
AI1422 Half-Frame Reader System User Guide 3. If a cable is used with the power meter, the cable loss must be determined by measuring all cables with an RF power meter of known accuracy. Calculate the resultant RF power levels using the formula dB = 10log P in/P out. Add this loss to the meter reading to determine the actual RF power output. 4. Set the ON/OFF switch located on the front panel of the reader system to on. 5.
System Test Procedures Figure 4-4 Typical Waveform with a Tag in the Reader Field Figure 4-5 depicts typical quiescent noise levels with the RF connector configured with a 50-ohm, 5-W terminator. Quiescent noise levels vary from unit to unit with channel C having the most representative noise level.
AI1422 Half-Frame Reader System User Guide Figure 4-6 Typical Beat Frequency Interference Waveform Reading the Tag To verify that the AI1422 Half-Frame Reader System is properly reading tags 1. Switch the ON/OFF switch located on the front panel of the reader system to off. 2. Using your own cable, connect the laptop PC to the reader system at the main RS–232 interface. 3. Connect the antenna to the antenna interface on the front panel of the reader system. 4.
System Test Procedures 11. Disable the trigger by disconnecting the jumper. 12. Set the on/off switch located on the front panel of the reader system to off. Note: Repeat this test several times. Each time, the lock LED should be lit and the PC should be reporting the tag data.
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5 Command Codes
Chapter 5 Command Codes This chapter describes the default and diagnostic command codes that enable you to develop host computer programs to control the functions of the AI1422 Half-Frame Reader System. Default Command Codes The default command codes enable communications between the host computer and the reader system. These codes, also referred to as the communications protocol, are in a binary format.
AI1422 Half-Frame Reader System User Guide Diagnostic Command Codes Diagnostic commands are used to check or fine-tune the reader system. Diagnostic Command Code Syntax Unlike default command codes that require a script file, diagnostic codes are typed by the user. The general syntax of diagnostic commands is to begin with an exclamation character, !, followed by the command code and a list of parameters.
Command Codes 3 4 5 6 = = = = 2400 baud 4800 baud 9600 baud (factory setting) 19.2 kbaud The response is !Done or !Error Note: The !Done response is issued at the setting that existed before invoking the new command. All subsequent communications will be at the new baud rate.
AI1422 Half-Frame Reader System User Guide mm = minutes (00–59) ss = seconds (00–59) The response is !Done or !Error Note: The time must be entered exactly as shown with no spaces between characters and colons as delimiters. All entries use decimal characters 0 through 9.
Command Codes Real-Time Transmission to Host Enabled (factory setting) !305 When a tag identification (ID) is acquired by the radio frequency (RF) source, it is immediately sent out on the RS–232 port. The tag ID is not stored in the data buffer. The response is !Done or !Error Transmit All Tag ID Codes !41 Command !41 transmits to the host computer all tag IDs received by the antenna. The response is !Done or !Error Note: This command is to be used for diagnostic purposes only.
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6 Troubleshooting
Chapter 6 Troubleshooting This section lists routine maintenance procedures to keep the AI1422 Half-Frame Reader System operating correctly and diagnostic procedures for troubleshooting an improperly working reader system.
AI1422 Half-Frame Reader System User Guide • Is the main power switch light-emitting diode (LED) lit? If not, turn on power switch. • Is the front panel fuse blown? If so, replace it with a 1.5 amp (A) slo-blo fuse. • Is the reader’s DC-DC converter functioning? If so, the OK LED on upper left corner of front panel will be lit. • Are you using a null modem cable connection? If not, switch to a null modem connection.
A Character Conversion
Appendix A Character Conversion Table A-1 lists the TransCore 6-bit-per-character conversion from the standard ASCII character set.
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B Technical Specifications
Appendix B Technical Specifications Table B-1 lists the specifications of the AI1422 Half-Frame Reader System. Table B-1 AI1422 Half-Frame Reader System Specifications Specification Description Size 19.0 x 5.25 x 9.0 in (48.3 x13.34 x 22.9 cm) Weight 12.0 lb (5.4 kg) Operating temperature +32°F to +158°F (+0°C to +70°C) Power requirement 13.5V DC ±1.0V DC @25W Available frequency range 902–928 MHz Approved frequency range for Federal Communications Commission and Industry Canada 902.25–903.
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C Diagnostic Command Codes List
Appendix C Diagnostic Command Codes List Command Function !~~CC Escape (CC must be entered in upper case) !100x Baud Rate Select !101x Stop Bits !102x Parity Select !20hh:mm:ss Set the Time in the Real-Time Clock !21MM/DD/YY Set the Date in the Real-Time Clock !22 Display Time and Date !305 Real-Time Transmission to Host Enabled (factory setting) !41 Transmit All Tag ID Codes !63 Return to Default Command Codes !642 RF Follows Trigger C-3
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