This chapter describes the usage of the PROMOTIC system in virtual computers. What is a virtual computer? Usually it is a system where there are multiple (independent) instances of a operating systems running on a single server (hardware) that appear as independent hardware platforms (while this is physicaly still a single server).
Virtual computers then allow to separate individual systems/applications in order to prevent them from influencing each other and to protect the operating system of the physical computer (server) itself.
For this purpose, there are multiple virtualization tools available: for example Microsoft Virtual PC
by the Oracle
company, or VMware
. Some of these tools must be installed on the host system (HOST
). In the virtual PC environment, it is possible to install additional hosted operating systems (GUEST
Specificity of operating the PROMOTIC system in virtual environments
The PROMOTIC system is very often used for data acquisition from different subordinate systems connected to the computer via Ethernet or via the computer's serial port (RS232/485
). The PROMOTIC application usually needs a licence to run, see PROMOTIC licence carrier types
. It it is necessary to understand that the GUEST
systems usually have limited access to the physical devices of the computer (network card, USB
ports) and therefore the access for example to serial or USB ports of the computer may be limited or denied.
The possibility to make these physical devices available for HOST
computer in the virtual environment is dependant on the virtualisation tool that is being used. Some tools cannot allow usage of USB and in such cases it is necessary to consider different ways of the PROMOTIC system licencing, for example the PmLicServer
If the USB HW Key or serial port can be used in the virtual computer, then it is necessary to understand that using these in the virtual computer means that this haedware will not be available for HOST
computer or even for another virtual computers running on the same physical computer. It means that the physical hardware can be dedicated only for a single computer (physical or virtual).
Let the virtual PC have access to the HW Key
permanently. This can be achieved by software means (accesing the USB on physical HOST
of the computer as USB in virtual GUEST
computer) or by means of another HW device that allows to operate virtual USB ports via network (Ethernet
Possible solutions of licencing the running application on a virtual PC.
The virtual computer (also accessed via the RDP
protocol - PROMOTIC system and Windows remote desktop (RDP)
), all licence carriers can be used, see PROMOTIC licence carrier types
. In such cases, it is necessary to use the local or network service PmLicServer licence server
Only if the application is operated as a service with GUI accessible only via the Web then the licence on hwkey - Hardware (USB) licence key
carrier can be read directly without the PmLicServer licence server