All about transponders
The transponder is used to identify a person in a race by sending a unique digital code when required to an RFID reader. Transponders come in all shapes and sizes and work at all kinds of frequencies. RFID Race Timing Systems use two specific type of transponder that are perfect for sports timing. Both are passive transponders meaning they do not use a battery to transmit their signals to a reader.
Low Frequency Half Duplex 134Khz
Developed by Texas Instruments in 1993 this transponder has been extremely successful in animal identification and sports timing. Excellent reliability and readability under field conditions. The transponders are hermetically sealed in a glass capsule and can be read under water if necessary. The downside to low frequency is that only one transponder code can be read by a reader at any one time. Sometimes a transponder may fail to read if two transponders are in the same read field. However techniques are used to avoid this problem by ‘locking on’ to the closest transponder and using multiple receiver loops attached to multiple reader circuits.
UHF Transponders (868 – 950MHz)
These type of transponders generally use radiated electrical energy to transmit their information to a reader antenna and the read distances are substantially more than for low and high frequency transponders that use inductive coupling. A great deal of research and development has been devoted to UHF technology because the transponder (or tag) is usually low cost consisting of thin flexible copper antenna and tiny integrated circuit the size of a grain of sand. These transponders can be read in large numbers at the same time using anti-collision algorithms. These algorithms were further enhanced with the adoption of EPC Class 1 Generation 2 protocol amongst the world leaders in tag and reader manufacture. RFID Race Timing Systems had evaluated many forms of UHF tags and readers and until the Battery Assisted Passive (BAP) tag, we did not see a reliable future for this technology. However things have changed and the latest readers and BAP have been brought together in our world leading Ultra System.
How many athletes can I time?
This question is only relevant to the level entry Dual Antenna System which has just two receive antennas. We do not recommend using just one of these systems in races bigger than 200 competitors due to the increased risk of tag collision. The HDD and Ultra Systems can handle as many runners as you can fit across the antenna mats. This is typically around 700 runners per minute over a 4m wide mat.
Will the RFID Race Timing System be out of date in several years?
Over the years we have found that RFID Race Timing Systems do not go out of date rather the requirements of timers change. When events grow in popularity or different types of events are added to the timer’s range it is ultimately here that a move towards the new technology occurs.
The low frequency transponders have been the benchmark for sports timing for many years are still in regular use with pro timers and clubs alike. Our HDD System continues to be a great performer for all types of events delivering a robust timing platform with the economy of re-usable transponders.
The new ULTRA units with UHF technology can deliver a greater range of abilities such as being able to use of disposable tags, and now with the advent of ULTRATAG is also able to successfully time swimming and triathlon events. Although while we see the future being focused towards ULTRA we will continue to support timers successfully using low frequency technology.
Is there after sales backup?
Definitely. We not only have expertise in building the best timing systems, but also in timing events themselves. RFID Race Timing has been involved in timing triathlons and swim events for over 8 years. We understand the requirements for completing the task of timing your event – from entering race competitors, to publishing results in the right format and on the best medium. Any problems with systems will be rectified quickly and efficiently, even if we have to send over a replacement system quickly in case you have an event to time while your own system is repaired. Service plans are available after the initial 1 year warranty.
Can you modify the race software for our application?
Yes. If your event requires a particular format for data capture or results presentation, we can often work closely with our software developers to modify current software packages. Many of these improvements flow on in the form of software upgrades to current owners of the system.
What is the difference between low and high frequency transponders?
We use low frequency (134khz) transponders and readers which generally are the standard used for sports timing. They offer good read range, read focus of antennas and can penetrate most mediums other than metal. The 134khz system is half duplex meaning that only one transponder can be read at any given time over a antenna mat. However, if transponders are slightly staggered as they cross over the mat, they will both be read in the correct sequence. This is actually an advantage since it means that the correct order of transponders crossing the mat is recorded. Sprint finishes can be easily and accurately separated to 0.1 second resolution. The much more common high frequency transponders tend to be cheaper and full duplex meaning that many transponders can be read at the same time by one antenna. This type of system is favoured for tracking goods in a warehouse (ie. Walmart). This is because the system is cheaper, transponders are expendable and most importantly, all the information that is required is whether the item or goods are in the general proximity of the antenna and RFID reader. Read order is less of a concern other than on a checkout where the read range is generally quite short (less than 12 inches). Most high frequency transponders operate at 13.56 MHz and the bulk of research centre’s around UHF systems. Some of the claims from the UHF reader manufacturers seem impressive and RFID Race Timing has evaluated the latest UHF reader for certain sports timing applications. There are a few examples of high frequency RFID timing systems in the world but the major feedback is that they lack the accuracy of the low frequency systems. Active high frequency transponders give better reliability but they are expensive. To read more about RFID technology we suggest visiting RFIDusa which can explain many of the technical terms used in RFID.
What is the difference between Ultra and Chronotrack?
Both systems use UHF Generation 2 readers working in the same band for the country of deployment. The systems differ in the type of antennas used and most strikingly, the position of the transponder on the athlete. With Ultra there is no need to put anything on the shoe lace and worry about the athlete making mistakes with putting the tag on. The BAP tag used in Ultra sticks to the back of the existing race bib making the timing process more efficient and reliable. You only need to miss the finish time of 1% of runners to receive 200 angry emails post race. Many of these runners will have made an innocent mistake attaching their shoe tags on the Chronotrack system.
What is Tag Collision?
In RFID systems there are times when two or more transponders may simultaneously send their signal to a reader. If the signal frequency of these two transponders is the same and they are less than 8 centimeters apart, then the reader will have difficulty separating the information and neither transponder will be read. This is called a ‘tag collision’.
The TI 134kHz transponder that RFID Race Timing Systems uses is half duplex. This means that the transponder communicates in one direction. The advantage of half duplex transponders is that they can be read from a greater distance away from the reader antenna. To minimize issues with tag collision, our systems read at 20 times per second. The new HDD system improves things even more by installing numerous readers and antennas within the mat matrix. With 16 readers all reading 20 times per second, it becomes virtually impossible to miss a transponder due to tag collision. The HDD was designed to handle all athlete densities and in particular, those seen at the start line of large fun runs.
Is it true that ULTRA can use any type of UHF Tag?
Yes, Ultra can read any Gen2 protocol tag making it the most flexible and cost effective RFID-UHF timing system in the market.
Are there many tag suppliers, and what is the choice in tags available?
The world of RFID technology is considerably wider than the application for sports timing, and as such there are numerous producers of tags around the world. Due to the diverse nature of RFID users, many different options exist in disposable tags varying in size, style and price. RFID Race Timing has thoroughly researched the market and will provide guidance as to preferred suppliers for race timing. We also provide very competitive tags based on the volume discounts we have available to us.
Why do the competitors only use one type of tag?
Our competitors choose to have a single tag tied to their system, so they can become the sole supplier and control the price you pay for tags. The business model they operate is to discount their system prices knowing that once you are on board they will more than recoup the discount in inflated tag prices. Compare the savings on our online calculator and see the true price you are paying for your timing system.
Why are the competitor’s tags so expensive?
The price of our supplier’s tags is well below that of our competitors. The only reasons we can think of is that the manufacturing costs of their unique tags are dramatically more expensive, or they are taking advantage of the fact that if you have their system they have to pay their prices. We ask the simple question, why pay more than twice the price for the consumable tags when you don’t have to with ULTRA?
What is the big deal of a few more cents in tag price?
A few cents price difference multiplied by large numbers of competitors becomes significant amounts of money. Just think in a 50,000 competitor event, saving 10 cents is $5,000…..but a 60 cent/tag saving will be a cool $30,000 to your bottom line. We know that you can save this much in tag prices.
Can ULTRA be used for multisport events?
Yes, with the advent of our re-usable ULTRATAG, UHF is now a reality for multi-sport. Encapsulated in a specially designed ankle strap the ULTRATAG is a Gen2 RFID tag that is easily read by the ULTRA, perfect for swimming, triathlons and adventure races.