Dear all,

I have to work with AS-I protocol in one of our machine. I have read we can connect upto 64 slaves with A/B technology, can anyone tell me what is A/B technology?

Can anyone share the simple document to understand, what is this protocol, frame size, format etc.

What is the difference between AS_i safe and ASI module .. 

Please give me some guidance to understand basic better..

Thanks&Regards,

Hello List;

First, here are some links that contain enough basic information on As-i networks, its required or prefered components (flat cable, As-i power supply, modular slaves, As-i addressing module...) and its different specializations, such as As-iSafe:

https://en.wikipedia.org/wiki/AS-Interface

AS-Interface - Industrial Controls - Siemens

AS-Interface Systems - ifm

Next, As-i is maintained by an independant organization that helps to define, promote and develop it; here is the link:

www.as-interface.net/

I would suggest you look specially at their Knowledge Base tab, there are a lot of subjects covered that might enlighten you.

Now, a quick answer ot your first question: the first iteration of AS-i allowed an As-i master to connect to 31 slaves, with a mandatory data collection cycle of 5ms, over a dedicated profiled flat cable. Later on, since users prefered to connect more slaves to a single master, they created 2 channels named A and B in the As-i cycle, each capable of connecting to 31 slaves in alternance, so total the master could now connect to 62 slaves; the price for that adaptation was that the data collection cycle was extended to 10ms. That is what is called the A/B technology for As-i.

That should give you a good basis to ask for your next questions...

Hope this helps,

Daniel Chartier

Standard Slaves (Older Ver. 2.0) can use up to 31 Slaves & Extended Slaves (Older Ver. 2.1/3.0) can used up to 64 Slaves.

You can find all details in below link,

http://cmsapps.sea.siemens.com/controls/icc2010/10IndControl_%20pdfs/10IC_14/09IKPI_06/06_005-006.pdf