Wireless Profibus

Question 1

What does Black Channel mean?

Answer

What does Black Channel mean?

The black channel principle allows the transmission of safe and non-safe process data over the same network or bus line. Regardless of the regular data transport mechanism used on this line, safety components can transmit data using an isolated safe protocol that tunnels through the underlying network channel. Since safe fieldbuses are pure application protocols without their own physical properties, the available bandwidths and cycle times depend on the data transport protocol used. Possible transmission errors are known and are listed in the relevant standards IEC 61784-3 and IEC 61508.

What does this mean for PROFIsafe?

The PROFIsafe protocol has no repercussions on the standard bus protocols. It is intended to be as independent as possible of the respective transmission channel, whether copper cable, fiber optic cable, backplane bus, or wireless. Neither the transmission rates nor the respective error detection plays a role. For PROFIsafe, the transmission channels are merely “black channels”.

Secure data transmission by radio: the black channel principle in detail

This means that the use of wireless technologies is also provided for and possible by definition, just like other radio technologies. Both the safety controller and the remote IO system – for example a safety switch – contain the safety protocol. The interface between them is merely the channel for transmitting the safety information. Accordingly, no safety certification is required for the wireless device and it is treated like other infrastructure components, such as switches or cables. This makes the recalculation or verification of the safety level (SISTEMA) for using a black channel solution obsolete.

Wireless PROFIsafe – Black Channel Principle

Question 2

Is radio a good alternative to a PROFIBUS slip ring?

Answer

Slip rings transfer power and data from a stationary unit to rotating objects where cables with their fixed connections cannot be used due to movement. Often in the past, such slip rings have helped solve challenges in the design and construction of rotating applications such as turntables. At the same time, their functional principle, which requires permanent electrical contact, is only suitable for the transmission of data to a limited extent: while short interruptions in the power supply usually do not pose any problems, in data communication between controllers they mean delayed or lost telegrams, which lead to errors and, as a consequence, often to plant standstills. Another disadvantage of data transmission via a slip ring is the wear caused by the grinding of the materials against each other.

For pure power transmission, slip rings and rotary unions remain good alternatives. They can be optimally supplemented with radio solutions, for example. As a result, power transmission and data communication are then separated, which has a positive effect on the stability of the solution and reduces EMC interference. As a rule, the combination of slip rings for power supply with radio solutions for data communication is also significantly cheaper than slip ring systems that can simultaneously transmit power and Ethernet protocols such as Profinet. This retrofit ensures a step-by-step modernisation of existing slip ring transmissions without high investment hurdles.

– Read the complete blog post

Question 3

What distances are possible with wireless PROFIBUS communication?

Answer

Depending on the choice of radio technology, a radio system can achieve a range of between a few metres and approx. 3 km. The line of sight and the antennas play a major role here. With DATAEAGLE radio systems, wireless PROFIBUS communication with (869MHZ (Europe) / 915 MHz (America) up to 3 km and with Bluetooth (worldwide usable) up to 1 km are possible.

– More about this in our product information/technical data

Product	Frequency	Typical distance (m)	Max PROFIBUS DP speed	max. Radio Slaves	max number PROFIBUS DP Slaves	Profisafe	PROTECTION CLASS
DATAEAGLE Classic 3712A	2,4 GHz	300	1.5 MBit/s	4	8	Yes	IP20
DATAEAGLE Classic 3713A	2,4 GHz	300	1.5 MBit/s	4	4	No	IP20
DATAEAGLE Classic 3715A	2,4 GHz	300	1.5 MBit/s	1	4	No	IP20
DATAEAGLE Compact 3333A / 3343A	869 MHz, 915 MHz	3000	1.5 MBit/s	4	4	No	IP20
DATAEAGLE Compact 3710 Starterkit	2,4 GHz	300	187.5 kBit/s	1	1	No	IP20
DATAEAGLE Compact 3712A	2,4 GHz	300	1.5 MBit/s	4	8	Yes	IP20
DATAEAGLE Compact 3713A	2,4 GHz	300	1.5 MBit/s	4	4	No	IP20
DATAEAGLE Compact 3715A	2,4 GHz	300	1.5 MBit/s	1	4	No	IP20
DATAEAGLE X-treme 3333A / 3343A	869 MHz, 915 MHz	3000	1.5 MBit/s	4	4	No	IP65
DATAEAGLE X-treme 3710 Starterkit	2,4 GHz	300	187.5 kBit/s	1	1	No	IP65
DATAEAGLE X-treme 3712A	2,4 GHz	300	1.5 MBit/s	4	8	Yes	IP65
DATAEAGLE X-treme 3713A	2,4 GHz	300	1.5 MBit/s	4	4	No	IP65
DATAEAGLE X-treme 3715A	2,4 GHz	300	1.5 MBit/s	1	4	No	IP65

Wireless Profibus

PROFIBUS via radio

DATAEAGLE 3000 – Wireless PROFIBUS