opinions and experiences of ASi-Interface

I first used the ASi network about 6 years ago, in fact we were ifm electronics first customer in the uk, we have now got about 15 networks in operation each with varying loads.

I for one am very happy with the technology, it will not do tasks that we expect profibus, modbus etc and industial ethernet do with ease, like plc data transfer, but what it is great for is transfering small ammounts of digital (and some analog) data over distributed networks.

I would use it when:-
I have several machines that are spread out over a distance of about 100m and have about 4I/4O each or 2-4 analog outputs.

I would not use it if:-
Dense I/O is needed(more than 16I/16O, or more than 4 analog chanels), fast response time is required (quicker than 100ms)

I have used Pneumatic modules, these are fantastic when used instead of solenoid valves, as they both handle the on off action required for the air, but can also handle the positioning input from the valve.

I have used analogue modules for temperatures and pressures which cope well and are very easy to program (when using ASi 2,1)

Digital input / output modules are great and speak for themselves.

Any other questions please ask!

Oh if you have not noticed, I love ASi. It is what it is, a very simple network solution with no bells and no whistles, but does what it is meant to do very well.

Oh by the way, the majority of ASi modules no matter who sells them, IFM, Siemens, Festo etc are all made by the same company and re-badged.... actually a lot of companies don't even bother to re-badge them!

Thanx Barry, what about Circuit Diagrams and Cabling documents, are they necessory or is I/O-list enough, if you can see Asi-Node address, connector number and abs. I/O address for programming ?

Seppo,

Since the system is only a 2 wire system (can be 4 if you need auxillary power) circuit diagrams are very easy, the order in which the slaves are placed on the ASi cable does not matter.

They don't have to be:-

1 - 2 - 3 - 4 - 5 - 6 - 7

They can be

31 - 1 - 17 - 13

It makes no difference, so as long as you identify which module is connected to what sensor or actuator and has which slave address that is normally sufficient.

If you wish I can send you a sample of our circuit diagrams on monday.

Regards

Barry

The total scantime for a network with 31 slaves is 4.8ms. If you use the "new" a & b channels, it will double the number of slaves and the scan time. Still, 10ms is quite fast.

The addressing is quite simple. If your starting address in the PLC is 0, your adressing goes left to right. 4 bits IN and 4 bits OUT 0,1,2,3,4,5,6, etc. Adress 0 is reserved. The BYTES are split into NIBBLES (1/2) BYTES. 1 NIBBLE per slave. The first word would contain 0 (reserved) ,1,2,3 the next word 4,5,6,7

If you were to remove address #5 and replace it with a new module ( it's address 0) the ASI network will Auto-majically reassign it as #5.

The only complaint I have, the dianostics are limited.

Thank You RRobbins and Barry,

Some ASi-Master have qualified for remoted programming as local interlockings. Maybe it makes unnecessary confusing if part of PLC-program have remoted and main idea have in PLC itself ?

I will just add one more point to this thread:-

the maximum bus length is 300 metres.

RRobbins you said that the diagnostics are limited, I have used ASi once and from what I remember the diagnostics told me what ASi slave had failed, what more do you want?

Paul

The maximum bus length I thought was 100m then you could use an extender repeater per extra 100m.

I have had networks over 150m without repeaters however!

Barry

Barry

Seppo, I am not quite sure what you mean from this?

Click to expand...

There are Programming interface in some ASi-Master units (IFM) and makes possible 'local' program in Asi-Master itself. Main program could be in PC, PLC or DCS.
My English is not well, so try follow my 'mind'. I meant program is partly 'distributed' to ASi-Master units for example through ProfibusDB.

If I understand its is not necessary transfer outputs from PLC to ASi-Master whoes have programmed in ASi-Master as well as Inputs, but for SCADA etc. maybe needs them for information.

I think what he is trying to say is that some of the ASI controllers can also be programmed like a PLC to control the outputs on the ASI bus while at the same time sending information back and forth from a main PLC over a Profibus Gateway. I've seen this available on a Pepperil and Fuchs model but that is the only brand I am familar with.

Some ASi modules will have some logic, processing built in for example a fast encoder input card, the input from the encoder is too quick for ASi, so the card has to take the input and analyse it and then transmit something that the ASi network can deal with. Very much like a PLC card (Fast PID input for example) that does more than just transmit data to the CPU.