Title: 32 Pumper modbuss teknisk data.pdf.pdf
The protection against unauthorised data access is high. The access to the APN network from the Internet can only take place via the VPN tunnel. See fig. 25. Moreover, data transfer requires a Modbus master client, knowledge of the Modbus functional profile and the use of a SCADA PIN code, if enabled.CIU 260 supervises the APN connection to ensure that it is still working. An automatic procedure ensures restarting of CIU 260 and repetition of the APN connection sequence in case aClientsVPN tunnelLANInternetSCADA systemGRE routerPC Tool, etc.Fig. 25 Cellular connection via VPN tunneldeadlock situation has occurred. It also closes down socket connections that are left open by the client and unused for more than 24 hours.It is possible to use SMS communication while data communication is active. However in the "Connected" state, the delay time between reception and reply increases.