Rewritable TM1990A TM Card Ibutton for Hotel Locking:
The TM1990A is a rugged data carrier that serves as an electronic registration number for automatic identification. Data is transferred serially through the 1-Wire® protocol, which requires only a single data lead and a ground return. Every TM1990A guaranteed unique 64-bit registration number that allows for absolute traceability. The durable stainless-steel iButton package is highly resistant to environmental hazards such as dirt, moisture, and shock. Its compact coin-shaped profile is self-aligning with mating receptacles, allowing the TM1990A to be used easily by human operators.
Key Features:
| Failure Rate |
1 /100,000 times ( used properly) |
| Original Serial Number |
64 bits |
| Security |
64 bits encrypt passwords |
| Memory Capacity |
8 K bits RAM |
| Read-Write features |
read, write and encrypt |
| Read-Write Endurance |
> 1.5 billion |
| Working Temperature |
-40 ºC~+85 ºC |
| Read Endurance |
> 350 thousand times |
| Working Time |
>20 years |
| Size |
φ16.25mm×5.89mm |
| Unit Weight |
0.05kg |
The basic principles of TM cards:
A TM card is similar to a button battery in shape and can be inlaid into a card, key button and other objects.
You can replace the data line, address line, control line and power line with a single line so that TM card achieves single line communication through a multi-function device. When the host is powered, TM card gives the response to the host through switching the impedances between 50Ω and 500,000Ω. The lengths of time the signal is pulled down(long or short) show the digital logics(long=1, short=0). Due to the range of witching impedances is 1-10,000, the resistances of the contact points will not affect the identification of the digital signals.
According to whether the Memory in TM card is encrypted or not, TM card can be divided into encrypted TM card and non-encrypted TM card.
Most of TM cards are non-encrypted.
TM1990-F5 card is an encrypted card: which is divided into three separate encrypted sectors. Each encrypted sector has its own password and the three sectors can be respectively used for three separate purposes. DS1982 card is programmable.
TM card's encrypted method is different from Contactless IC Encrypted cards: The former has 64-bit password without the function of error calculation, while the latter has shorter password and the function of error calculation. If you forget your password by chance, you can reuse your TM card after re-initializing it, but the information in your card will be automatically rewritten.
Common iButton Features
Unique 64-Bit Registration Number Ensures Error-Free Device Selection and Absolute Traceability Because No Two Parts are Alike
Built-In Multidrop Controller for 1-Wire Net
Digital Identification by Momentary Contact
Data Can Be Accessed While Affixed to Object
Economically Communicates to Bus Master with a Single Digital Signal at 16.3kbps
Button Shape is Self-Aligning with Cup-Shaped Probes
Durable Stainless-Steel Case
Easily Affixed with Self-Stick Adhesive Backing, Latched by its Flange, or Locked with a Ring Pressed Onto its Rim
Applications/Uses
Access Control
Inventory Control
Tool Management
Work-in-Progress Tracking
Package:
Audited Supplier 
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