iButton DESCRIPTION
The DS1992/DS1993 memory iButtons (hereafter referred to as DS199_) are rugged read/write data carriers that act as a localized database, easily accessible with minimal hardware. The nonvolatile memory and optional timekeeping capability offer a simple solution to storing and retrieving vital information pertaining to the object to which the iButton is attached. Data is transferred serially through the 1-Wire protocol that requires only a single data lead and a ground return.
The scratchpad is an additional page that acts as a buffer when writing to memory. Data is first written to the scratchpad where it can be read back. After the data has been verified, a copy scratchpad command transfers the data to memory. This process ensures data integrity when modifying the memory. A 48-bit serial number is factory lasered into each DS199_ to provide a guaranteed unique identity that allows for absolute traceability. The durable MicroCan 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 DS199_ to be easily used by human operators. Accessories permit the DS199_ to be mounted on almost any surface including plastic key fobs, photo–ID badges, and PC boards.
Applications include access control, work-in-progress tracking, electronic travelers, storage of calibration constants, and debit tokens.
SPECIAL FEATURES
4096 bits of Read/Write Nonvolatile Memory (DS1993)1024 bits of Read/Write Nonvolatile Memory (DS1992)
256-bit Scratchpad Ensures Integrity of Data Transfer
Memory Partitioned into 256-bit Pages for Packetizing Data
Data Integrity Assured with Strict Read/Write Protocols
Operating Temperature Range from -40°C to +70°C
Over 10 years of data retention
COMMON iButton FEATURES
Unique, Factory-Lasered and Tested 64-bit Registration Number (8-bit Family Code + 48-bit Serial Number + 8-bit CRC Tester) Assures Absolute Traceability Because No Two Parts are Alike
Multidrop Controller for MicroLAN
Digital Identification and Information by Momentary Contact
Chip-Based Data Carrier Compactly Stores Information
Data Can be Accessed While Affixed to Object
Economically Communicates to Bus Master with a Single Digital Signal at 16.3kbps
Standard 16mm Diameter and 1-Wire® Protocol Ensure Compatibility with iButton® Family
Button Shape is Self-Aligning with CupShaped Probes
Durable Stainless Steel Case Engraved with Registration Number Withstands Harsh Environments
Easily Affixed with Self-Stick Adhesive Backing, Latched by its Flange, or Locked with a Ring Pressed onto its Rim
Presence Detector Acknowledges When Reader First Applies Voltage
Meets UL#913 (4th Edit.); Intrinsically Safe Apparatus, Approved under Entity Concept for use in Class I, Division 1, Group A, B, C and D Locations
