Maximize the limit of AS-i network: What to be consider

[ryanbestgarcia]

I have here a proposed network of AS-i..
take a look of my attached file.

Module:
Master and Slave are v2.1

1. Is this network set-up is possible?

2. Do i have to used extra power supply (the BLACK CABLE)
considering that my input are only switches and sensor / and my output are relay and terminal connection of VFD,s?

 

[kiwi sparky]

According to
http://www.ca.pepperl-fuchs.com/pdf/documents/van-115-power-supplies-repeaters.pdf
max combined distance from master to 1st repeater is 100m. If star network (as you have drawn it) is used you have to add 5+95+95+95. So you would be over the max.
Also you have drawn 62 slaves. This would max out the network if they are extended slaves (A and B Slaves) and double the network max if they are non-extended slaves.
I wouldn't advise maxing out any ASi network, especially if you are using it for safety.

I would always use auxillary power for outputs (extra black cable) especially with the number of slaves you are talking about

 

[ryanbestgarcia]

thanks for the reply....
I'm just curious for the FAQ of as-i on their official site
http://as-interface.net/System/Experts#en-4
Can I install several repeaters in different network-arms?

Yes, in that case it is possible to extend the network up to 500m (Master is located in the middle sector of the network).

How come they arrived at 500 meters?is it a mixed up of EXTENDER and REPEATER?

tnx for the additional reference, the maximum repeater if ur using star topology is 7? based on the manual u gave?

 

[TurpoUrpo]

AS-i--Repeater--AS-i--Repeater--AS-i--Master--AS-i--Repeater--AS-i--Repeater--AS-i

I try to illustrate the 500m. You put master on middle, then in both directions at 50m repeater, and then another repeater on after 100m and then you get 100m more. So 2*(50+100+100)=500m.

 

[Nick B]

The grey hair on my head tells me your flying to close to the sun young man. You can do 300M with repeater but with all the repeaters and slaves you are pushing the envelope.

See link: http://support.automation.siemens.com/US/view/en/28383163

I would suggest two ASI Masters. Also put terminators (Extenders) at the ends of your network.
https://mall.automation.siemens.com...-5609-1-5611-5612-5652-5741-5743-&jumpto=5743

Just out of curiosity what PLC are you proposing to use?

 

[ryanbestgarcia]

i will be using s7-300, cpu315-2dp and a cp343-2p...and my slaves will be IFM..
My first plan is to use 2 master that's why i post here if what will be the consideration if i will maximize the technology of AS-i..

thank you very much to all of you for all the response and it is very appreciated...

another question:

1.can you give me some computation and consideration when will i used the black cable?(the additional voltage)

2.I want this one to be clear also...i will used as-i power supply after the repeater and an ordinary power supply 24vdc for extra supply the black cable. Am i right?

tnx

 

[Nick B]

I use the Black cable based on whether I need it for the Slaves. For your lengths for sure. Step7 handles the AS-I stuff well.

For what it's worth I have seen a lot of problems with IFM slaves. I'm picky that way if I get burnt once I stay away.

Check this out...it's good. http://support.automation.siemens.com/WW/view/en/40737628

i will be using s7-300, cpu315-2dp and a cp343-2p...and my slaves will be IFM..
My first plan is to use 2 master that's why i post here if what will be the consideration if i will maximize the technology of AS-i..

thank you very much to all of you for all the response and it is very appreciated...

another question:

1.can you give me some computation and consideration when will i used the black cable?(the additional voltage)

2.I want this one to be clear also...i will used as-i power supply after the repeater and an ordinary power supply 24vdc for extra supply the black cable. Am i right?

tnx

 

[TurpoUrpo]

Well i did not suggest using 500m, i just told how its possible. I would not do it. Not worth to save few hundred on not buying second master(or dual master), then have plant down becouse of that.. And lose many times more.