AS2702 (SAP4.1) is a new generation AS-Interface slave device, which supports AS-Interface bus systems with up to 62 slave modules.

Each slave module is equipped with an AS2702 device, which interfaces the module to the unshielded 2-wire ASInterface bus for serial bidirectional data communication and power extraction.

Data communication over the AS-Interface takes place in master slave fashion, which foresees that all slave devices AS2702 connected to the bus are sequentially and cyclicly addressed by a single, central master unit. Data on the ASInterface bus are Manchester encoded and can be found as sin2-pulses with a Vpp of between 3V and 8V on top of the bus’ dc voltage of nominally 30V.

AS2702 regulates the nominal dc bus voltage of 30V internally down to 5V to supply it’s internal circuitry including a 16 x 8 bits EEPROM, as well as down to a nominal supply level 24V with a max. loading of 35mA for the actuators and sensors connected to it at the field side.

Each slave device AS2702 may interface to up to 4 sensors or 3 actuators. An AS-Interface bus system based on AS2702 may hence link as many as 248 sensors and 186 actuators to a single master unit.

Slave device AS2702 (SAP4.1) is system compatible with predecessor device AS2701A (ISA3+): slave modules equipped with AS2702 (SAP4.1) will run in existing AS-Interface bus systems based on AS2701A (ISA3+).

The AS-Interface concept is well established as a standardized digital bus system for industrial automation.