VARAN is solved in hardware
The real-time bus system VARAN operates according to the manager/client principle. In each network, there is a manager that initiates all communication. Whereby packet collisions are avoided.
To the manager, the entire network appears as a 4-GB memory space in which the participant (client) is assigned a virtual memory area. The network can contain up to 65,280 clients. To perfectly utilize existing networks, TCP/IP cross traffic was integrated.
The basic structure VARAN is implemented the same for managers and clients. The VARAN protocol is completely implemented in the hardware FPGA and serial SPI Flash.
![](https://www.varan-bus.net/wp-content/uploads/2017/12/E_Grafik_Komponenten_VaranAnbindung.png)
VARAN Manager: One manager controls everything
VARAN is based on IEEE 802.3 100TX standard Ethernet technology, over which the VARAN security layer lies. This provides the data packets with a checksum and guarantees consistent transmission.
Each data transfer is initiated exclusively by the VARAN Manager and centrally administrated. The manager has multiple areas – separated by priorities: Direct Access (DA), Asynchronous (ASYN), Isochronous (ISO).
All protocol-specific VARAN Manager tasks are processed in the FPGA. This reduces the burden on the control CPU.
![](https://www.varan-bus.net/wp-content/uploads/2017/12/E_Grafik_VaranManager_OSI_Modell_2spaltig.png)