Die FAQ-Seite in Deutsch.

General Queries (G)
Q(G1): Has BiSS been designed exclusively as an encoder interface for motion control systems or are other applications possible?
A(G1): BiSS is predestined for use as a real-time motion control interface. However, BiSS's extreme flexibility and low implementation costs also open up other new areas of application, making it suitable for general use with sensors and actuators, for example.

Q(G2): What should I expect in the way of hardware costs for BiSS I/O nodes?
A(G2): The hardware required by BiSS has been kept to an absolute minimum. Standard pin connections with 6-wire cables are used; a signal conversion circuit and the BiSS interface can be integrated onto a single chip and ordered from any reputable semiconductor manufacturer (such as iC-Haus) at a relatively low cost.

Q(G3): What's the quickest way to go about implementing BiSS?
A(G3): iC-Haus can supply you with a demo board for initial experiments with BiSS. This enables you to effect a complete lab setup of the application on your own premises. Third party support is also available on the internet at http://www.biss-interface.com.

Q(G4): How many subscribers can be operated on a BiSS system?
A(G4): The maximum number slaves to be connected up to a BiSS master is 8 in BiSS-B protocol and principially unlimited for C protocol.

Q(G5): How is the integrity of transmitted data verified?
A(G5): Digital signal transmission enables data telegrams to be monitored for plausibility using CRC bits. This guarantees a high level of data integrity.

Q(G6): What were the main reasons for developing BiSS?
A(G6): The development of BiSS was instigated by market demands for a non-proprietary, flexible interface. Performance and transparency of cost were the chief concerns governing the engineering process.

Q(G7): Who monitors the conformity of BiSS devices?
A(G7): Primarily this task falls to the manufacturers of BiSS devices themselves in conjunction with master/slave reference components supplied by iC-Haus, for example.

Q(G8): Where does BiSS position itself between controller and field bus level?
A(G8): BiSS covers all known encoder interface applications, cuts costs, has various additional uses and even allows several sensors and actuators to be connected up on one line. Below field bus level, as a controller-free subnetwork BiSS can act as a fast data collector for smart sensor technology.

Q(G9): What is entailed when implementing BiSS on the controller and the sensor side of a device?
A(G9): The controller operates as master for which ca. 5,000 gate functions are sufficient to operate a single BiSS participant. A slave requires ca. 1,000 gate functions only.

Queries On Licensing Issues (L)
Q(L1): Are license fees charged for the use of BiSS?
A(L1): End users and BiSS device manufacturers will not be hampered by license fees or any other hidden costs. BiSS is an open-source, non-proprietary interface. License fees may become valid for those IC manufacturers who freely market ICs with implemented BiSS interfaces.

Q(L2): How do I obtain a BiSS manufacturer ID?
A(L2): A registered manufacturer ID is issued free with the license on entering into the BiSS Device Manufacturer License Agreement or BDMA.

Q(L3): Can I implement the BiSS protocol without taking out a license?
A(L3): In principle, yes, you can. The open protocol is available as a device-internal communication solution, for example. The implementation of integrated components (from licensed IC manufacturers) is also unaffected here.

Q(L4): What do I need a BiSS license for?
A(L4): By securing a free BiSS license you obtain the right to use BiSS, granted marketing rights (the use of the name "BiSS interface" and corresponding logo) and duplication rights for documentation purposes, you are issued with a registered manufacturer ID and can access technical support from IP modules (in VHDL, C++ and XML), for example. License holders pledge to conform to the BiSS protocol on implementing their BiSS applications, to document any further developments and to make these accessible to interested parties.

Queries On Technical Details (D)
Q(D1): How fast is data transmission with BiSS?
A(D1): The highest possible clock rate is limited by the transmission loss. With 50 meters of cable, for example, clock rates of up to 10 MHz are not a problem (using RS422 standard drivers and twisted-pair cables). This example has an effective data rate of 8 MBaud for sensor data and of 60 kBaud for bidirectional register data. 35-bit sensor data can be transmitted in cycles of 10 ┬Ás. BiSS speeds up at LVDS-levels to 100 MBit/s depending on the drivers used.

Q(D2): The BiSS protocol has no timing references. Which sensor timeouts and which clock frequencies are advisable here?
A(D2): The protocol itself has no time limits such as those which are forcibly generated in hardware implementation. BiSS Application Note #2 gives recommendations.

Q(D3): Is BiSS restricted to use with RS422 hardware?
A(D3): No. Other physical implementations are conceivable, like LVDS.

Q(D4): Does BiSS have specifically designated register areas?
A(D4): A BiSS master requires the manufacturer and device ID to be at addresses 78h to 7Fh in the first register block used (128 bytes per slave ID). With BiSS C there are more registers reserved for dedicated information: bank selection, EDS bank pointer, BiSS profile identification and serial number. All other areas can be defined as required regarding device configuration and EDS regulations.

Q(D5): Which commands does BiSS recognize?
A(D5): BiSS is not command driven. With regard to the communication of sensor data BiSS only recognizes data capture actions triggered by clock signals. The bidirectional register access brings read and write access.