The following provides the major specifications of the bus of AS-Interface V2:
1. Slave Addressing: every slave linked to the bus AS-Interface have to have an address between 1 and 31, escorted by "bank" /A or "bank" /B for extensive addressing. The slaves distributed from the factory have the address 0. Addresses are programmed via a specialized terminal of addressing.
2. Slaves Identification: All slave devices associated to the bus of AS-Interface are recognized by:
• A code of ID identity that specifies the slave type such as sensor, extended slave, etc.
• A code of I/O that confirms distribution of input/output.
• A code of ID2 that specifies the slave internal functionalities,
• A code of ID1 that specifies an additional identity of slave,
3. Slaves and inputs/outputs maximum number
A bus of AS-Interface can support a maximum on the same bus of:
• 31 slaves with standard settings of address; with addresses from 1 to 31,
• 62 slaves with extensive settings of address; every slave can have a maximum of 4 inputs and/or 3 outputs, the addresses are from 1 A/B to 31A/B.
4. AS-Interface Bus Topology and Maximum Length
The AS-Interface bus topology is flexible. It can be completely adapted to gather the user’s requires. The total length of all the branches of the bus has to not go over 100 meters without a repeater.
5. The Cycle Time of AS-Interface Bus
This is the cycle time between the module of master and slave. The system of AS-Interface always transfers information, which is the same length to every slave on the bus. The cycle time of AS-Interface depends on the active slaves number that connected to the bus. The scan time t stands for the time of exchange between a master and n active slaves. So, for:
• The active slaves up to 19, t = 3ms
• The active slaves 20 to 31 t = (1+n) * 0.156ms. This means that for 31 extensive address setting slaves constructed in /A, + 31 extensive address setting slaves constructwd in /B. the time of scan will be 10 ms.
Maximum cycle time:
• For 31 standard or extensive address setting slaves, maximum 5 ms
• For 62 extensive address setting slaves, maximum 10 ms.
6. Flexibility and Reliability
The process transmission utilized guarantees dependable operation. The master observes the data sent and the line supply voltage. It notices transmission errors as well as failures on slave, and transmits the information to the PLC. The slave exchange or connection of a new slave during operations does not disturb communications with the other slaves.