Allied Telesis AR750S-DP Secure VPN Router - Manual (Page 48)

Installation and Safety Guide
47
Connection to ISDN network
Ports for the connection of other apparatus
The following interfaces normally operate at SELV (Safe Extra Low Voltage)
levels:
■ Asynchronous (console) ports
■ Ethernet ports
■ G703 ports
■ Synchronous ports
Note SELV is a secondary circuit whose voltages do not exceed a safe value
under normal operating conditions and under single fault conditions. Under
normal operating conditions the voltages do not exceed 42.4 V peak AC or
60 V DC.
TNV1
The following interfaces are Telecommunications Network Voltage (TNV1)
circuits, which operate normally within the limits of SELV:
■ BRI ports for connection to ISDN Basic Rate telecommunications networks
■ PRI ports for connection to ISDN Primary Rate telecommunications
networks
■ E1/T1 ports for connection to E1/T1 services
Note A TNV1 circuit is a circuit which under normal operating conditions does
not exceed the limits for SELV and on which overvoltages from
telecommunication networks are possible.