EUCHNER EKS FSA with USB Interface - Manual (Page 36)

Manual EKS Electronic-Key Adapter USB
Page 36/44 Subject to technical modifications 094485-04-11/13
8 Operating the Electronic-Key-System with the aid of the
virtual COM port
8.1 Special features of the USB interface
The USB interface is designed as a virtual serial COM port. The communication is exactly the same as for the
device with serial RS232 interface.
If there is an Electronic-Key within the operating distance of the Electronic-Key adapter, the LED on the front
changes from green to yellow. At the same time the CTS handshake signal changes from inactive (0) to active
(1). This signal corresponds to the CTS / OUT signal with RS232 level on the Electronic-Key adapter with serial
interface. This signal can be used for control purposes to detect whether there is an Electronic-Key in the
Electronic-Key adapter.
8.2 Communication
This section primarily describes communication between a PC and the Electronic-Key adapter (referred to as
the device in the following).
Communication with the Electronic-Key adapter is performed via a virtual COM port. The commands are sent
over this COM port. It is possible to communicate with several devices over different COM ports. In principle
COM 1 to COM 128 can be used.
The transfer messages for the commands
 Program (write) Electronic-Key
 Read Electronic-Key
are based on the transfer protocol 3964R [1]
Integration of the Electronic-Key Adapter with USB interface into the user’s PC application is supported by an
optionally available ActiveX
 module (order no. 098 708) (usable for MS Windows based programs with
ActiveX
 capability). EKS can thus be used in conjunction with process visualization. The ActiveX 
module is
used as a protocol driver for the 3964R data transfer protocol described in the following.