The AUTOCALL TFXnet™ system from SimplexGrinnell comprises a group of network interface modules and peripheral equipment that form a robust, fault-resistant and flexible peer-to-peer communications network.

Designed for high survivability, the AUTOCALL TFXnet system uses a token-passing communications protocol that treats each fire alarm node equally. Loss of one or more nodes does not affect operation of the remainder of the network, which is automatically reconfigured when a node is inserted or removed. Data is generated at each node with a minimum delay (1/2 bit time). This provides maximum distance between nodes and isolation of signaling circuits between nodes without impacting data throughput.

Isolation ensures that a short/open condition on a circuit between any two nodes does not affect other circuits. If groups of nodes become isolated from the remainder of the network, due to one or more circuit faults, each group will automatically reconfigure its communications and continue to inter-operate. When the fault condition is corrected, the network will reconfigure and re-commence total communications.

Features

• Half-duplex, token-passing protocol
• Networks up to 62 panels without a host or master controller
• Peer-to-peer operation
• Automatic fault recovery
• Field-configured baud rates - up to 38.4K
• Asynchronous - one-stop bit, eight data bits, no parity
• Deterministic performance
• Self-configuring
• Open/short circuit detection and location --isolated at each node
• Nodes automatically disconnect from network at loss of power or in catastrophic failure