The tres900 is a transponder and reader engineered system designed for RFID applications, particularly for vehicle access control and asset tracking. It functions as an RFID reader that emits radio frequency (RF) signals to power and read passive RFID tags, then transmits the collected data to a host system.

Technical Specifications

Power Requirements: The tres900 Reader operates on 8 to 16 volts DC (1.5A @ 12V). It requires a regulated, linear, or switching power source and should be operated from a grounded supply with the same ground reference as the host. The recommended power supply is the tres-PSS12-035, an 85-264VAC, 35W, 12VDC @ 3A regulated unit, which is typically supplied with each reader.

Wiring and Output: The reader features multiple wiring connections for various functions:

RS232 TX (Brown) and RS232 RX (White) for serial communication.
RS232 GND (Purple) for RS232 ground.
DATA1 (Yellow) and DATA0 (Green) for Wiegand output.
Ground (Gray) for Wiegand ground.
T1 (Blue) for Reader Control (Trigger Function).
Power +V (Red) for +8 to +16 volts.
Power -V (Black) for -volts ground.

Wiegand Output: The tres900 supports standard Wiegand protocol. Data 0 (GREEN wire) and Data 1 (YELLOW wire) normally rest at +5 volts and move to zero voltage (GRAY wire - Ground) for logic 0 or logic 1. Shielded, insulated, stranded wire is recommended for Wiegand connections: 22 AWG for distances up to 25 feet and 16 AWG for distances up to 500 feet.

Serial Output (RS232): The device provides a standard RS232 serial interface, allowing it to communicate with any computer that accepts RS232. Data is outputted through simultaneous ports and can be monitored using a terminal program that displays ASCII data. The default communication settings for the terminal program are 9600 baud, 8 data bits, no parity, and 1 stop bit (9600, 8, N, 1).

Cable Guide: Proper wire gauge selection is crucial for performance and reliability. The manual provides a cable guide to ensure minimal voltage drops (limited to 5% at a given distance in a 12V system) based on power consumption (W/VA/Amps) and distance. For example, a 5W/.42A load can be supported up to 2,222 feet with 8 AWG wire, while a 30W/2.50A load requires 8 AWG for up to 373 feet.

Usage Features

Installation and Mounting: The tres900 Reader comes with a mounting bracket designed for installation on poles (e.g., a 2-inch OD round pole), wood, concrete, or brick structures. The antenna should be aimed towards the desired coverage zone. A 3/8" (10 cm) wrench is the recommended tool for installation.

RFID Obstructions: The performance of the RFID system can be affected by obstructions. RF signals are absorbed by liquids, weakening the signal. Most materials like plastic, cardboard, wood, and paper have little impact. However, metal reflects and weakens the signal significantly, creating "radio shadows" or "dead spots." Ferroconcrete and metal/aluminum facings can severely reduce penetration (0-10% for metal/aluminum, 10-90% for ferroconcrete). It is crucial to ensure readers have a clear view of the tags.

Parallel Surfaces Rule: For optimal tag reads, the surface of the reader and the tag should be as close to parallel as possible. Passive RFID tags receive power from the reader's RF emission, accelerate the signal, and reflect it back. Parallel alignment facilitates this process, improving read performance. The manual provides an example where poor performance due to non-parallel alignment was resolved by repositioning the reader.

Tag Orientation - Vertical Plane: For optimum read range, tags must be vertically oriented. The antenna should be aimed at a spot down the road from the gate where tag reading is desired. The detection area increases as the vehicle approaches the gate. Windshield tags should be mounted on windshield glass for best performance.

Tag Vehicle Installation: Tags should be mounted in a vertical position for optimum read range. Windshield stickers should be placed 2 inches away from any metal posts on all sides. Users must ensure that the chosen location complies with all state and local vehicle codes/laws. A caution is issued for windshields containing metal, suggesting an exterior tag might be necessary in such cases.

Trigger Function: If configured for triggering mode, the reader will only read a tag when the BLUE trigger wire (T1) is tied to ground. This function is typically achieved using a Loop Detector or the tres Smartloop system to detect a vehicle's presence, enabling gate opening or acting as a safety device to prevent gate closure on a vehicle.

Power Level Control: The tres900 includes a utility program called "treslevel.exe" on the accompanying CD. This program allows users to control the reader's output power. For instance, if a 30-foot read range is achieved but only 15 feet is desired, the output level can be adjusted from 30.0 dBm to 20.0 dBm. The program connects to the reader via the RS232 port.

Tag Programmer: The tres900 system includes a tag programmer and software package. This allows the factory and users to program 26-bit Wiegand data onto EPC Gen2 inlay/credentials, including custom programming of various tag and credential types.

Maintenance Features

Troubleshooting Guide: The manual provides a comprehensive troubleshooting guide for common issues:

Unit not operating properly:
- Confirm audible beeper when a tag is presented or power is applied. If not, remove power.
- Check RED and BLACK wire installation.
- Verify voltage at the Reader pigtail cable to ensure sufficient power, especially if voltage drop due to cabling is suspected.
Reader beeps continuously (3 times per second):
- Indicates insufficient power from the power supply.
- Check voltage at the Reader pigtail cable; ensure it's between 8 and 16 VDC.
Reader does not recognize a tag (no beep, no outputted data):
- Test with another tag to rule out a damaged tag.
- Verify reader operations by connecting to a computer via the RS232 port and running a terminal program.
Tag data scrambled or reader beeping and host not responding:
- Verify correct wiring connections for Data 0 (GREEN), Data 1 (YELLOW), and ground (GRAY) between tres900 and the host panel.
- Ensure Earth Ground terminates at the back of the reader (via mounting brackets or power supply ground wire).
- Check if the cable length between the reader and panel exceeds Wiegand specifications.
- Confirm that the tres900 tag number and site code are properly programmed in the host panel.
- Verify Wiegand timing parameters are within SIA standard.
Read Range too short:
- Investigate potential ground loop issues; check if earth ground terminates at the reader. Test by powering the reader without the reader ground wire connected.
- Ensure tag orientation is vertical for maximum antenna performance and distance.

Shipping Box Contents

Each tres900 shipping box contains:

Bracket Assembly
Reader Assembly
Power Supply - tres-PSS12-035
Documentation on CD ROM
Printed Documentation (Quick Start Guide and a checklist)

All items are securely packed to prevent shifting during shipping, with particular attention paid to the bracket assembly.

Electromagnetic Interference (EMI)

The manual highlights the potential for electromagnetic interference (EMI) from power transmission lines. These lines can interfere with radio waves, affecting RFID, radio, and cell phone signals. Both electricity and RF transmit data at specific frequencies. EMI effects can be mitigated by shielding or burying transmission lines. Users are advised to contact their local power company for assistance in suppressing EMI.

Tres 900 - Page 19

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