Application
With the Electronic-Key system (EKS), it does not matter if a password is forgotten. EKS
Nowadays access rights are usually controlled by the issue of passwords. In practice, however, this often leads to unauthorized system interventions.
This is where the Electronic-Key System can be put to optimal use: in comparison to the issue of a password, considerably more responsibility is assigned to the owner of an Electronic-Key.
The Electronic-Key provides protection against unauthorized access to operation and visualization systems. Often only specific people have permission to change the system parameters on critical systems. This is the ideal application for EKS
In a typical application, the user has an access right at a specific level
An example:
- Stage 1: Start and stop installation
- Stage 2: Change process parameters
- Stage 3: Manage Electronic-Keys
The Electronic-Keys are available in different colors with identical functionality. The colors can be used, for example, to indicate the different levels of access rights.
Key management using the Electronic-Key-Manager
The Electronic-Keys can also be managed on separate workstations using the Electronic-Key-Manager (EKM) software.
Along with access rights or personal data, it is also possible to save process-related information, e.g. recipes or parameters for the machine control system, on the Electronic-Key and in the database and retrieve the data in production.
System overview
EKS basically comprises two components: an Electronic-Key and the matching Electronic-Key adapter.
Integrated into the Electronic-Key in the form of a robust tag are a memory chip and an antenna (transponder). This is an inductive Identification System with a transponder without battery.
In operation the Electronic-Key is inserted into the Electronic-Key adapter and is held in place by a spring clip. The power supply for the transponder and the data are transferred contactlessly between the Electronic-Key adapter and the Electronic-Key.
The data carrier in the Electronic-Key is equipped with a combined read/write and fixed-code memory:
- 116 bytes E²PROM (programmable) plus 8 bytes ROM (serial number)
The Electronic-Key adapter is a read/write system with integrated interface electronics. Device variants with the following interfaces are available for system connection:
- Serial RS232/RS422, switchable
- USB
- Ethernet TCP/IP
- PROFIBUS DP
- PROFINET
The Electronic-Key adapters with serial interface and Ethernet TCP/IP interface can be connected to a PC or a control system. The advantage of Ethernet is that EKS can be physically remote. The Electronic-Key adapter with USB interface is particularly suitable for connecting to a PC. The major advantage is that power is supplied via the USB connection.
The Electronic-Key adapters with PROFIBUS and PROFINET interface are preferably used on control systems. Also in these variants, the EKS can be used remotely from the control system, e.g. at assembly workplaces.
All the advantages at a glance
With EKS, very fast log-on is possible without the use of a password even on systems without a keyboard. In addition, it is sensible to program the application to permit system access only as long as the Electronic-Key is positioned in the Electronic-Key adapter. Then when the Electronic-Key is removed, e.g. access to specific functions on the system is automatically inhibited.
A major advantage is the flexibility of the system:
- Easy assignment and alteration of the access rights level
- Access for lost Electronic-Keys can be disabled
- Fast assignment of additional Electronic-Keys
Along with the level for the access rights, e.g. the name of the user can be programmed into the Electronic-Key read/write in plain text.
For quality assurance in accordance with ISO 9000, it is possible to log accesses and changes when using EKS.
The EKS system also makes it possible, for example, to log product parameters and operator entries in accordance with FDA standard 21 CFR part 11. EKS can be used in this context as an electronic signature for personal confirmation of work steps.
Due to the non-contact transfer of data, it was possible to design the Electronic-Key adapter from the access side with the high degree of protection IP 67, i.e. suitable for industry. The Electronic-Key adapter can be installed in accordance with DIN 43700 in any control panel with a standard cut-out of 33 mm x 68 mm. It is fastened by means of screw clamp elements from the rear side of the panel in order to exclude unauthorized manipulation from the operator side.
On Electronic-Key adapters that are used as pure read stations on the production line, write protection can be enabled using a DIP switch
Approvals
The EKS Electronic-Key adapters are certified according to 
(UL file number E240367).
Integration
The user is responsible for organizing the programming of the application, integration in an overall system and assignment and use of the freely programmable memory in the Electronic-Key.
Interfacing of the EKS Electronic-Key adapters with serial, USB or Ethernet TCP/IP interface to the user’s PC application is supported by optionally available ActiveX® modules 1) (can be used if Microsoft Windows®-based user programs support ActiveX®1)). EKS can thus be used, e.g., in conjunction with process visualization software. Data communication is in accordance with transfer protocol 3964R or TCP/IP. The ActiveX® module is used here as a protocol driver.
To operate the EKS Electronic-Key adapter with USB interface on a PC, USB driver software must be installed. The USB interface is designed as a virtual serial COM port. The communication over the interface is exactly the same as for the device with serial interface. Therefore devices with serial interface and USB interface are interchangeable with regard to software applications.
If a database is established to use the unique Electronic-Key serial number, it is not imperative to write to the Electronic-Key. As an option, the Transponder Coding software can be used for straightforwardly writing and reading the Electronic-Key on the PC. Furthermore, the Electronic-Key-Manager, a flexible software package, is available for programming and managing the Electronic-Keys on the PC including database for the Electronic-Keys. The freely programmable memory on the Electronic-Key can be structured exactly as required using EKM.
Commissioning and system integration is significantly easier using the EKS with PROFIBUS and PROFINET interface. The address can be set using DIP switches. The EKS is integrated in the software using the GSD files and the data are available in the control system's input area immediately after configuration.
(1) Microsoft Windows® and ActiveX®are registered trademarks of Microsoft Corporation)