AS-i 'Safety at Work'

SPS Steurung

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Jan 2008
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I am contemplating whether or not to use an AS-i Safety at Work system from IFM Efector to control all my safety devices on an upcoming project. I've never used nor seen a system in operation but it looks like a real time saver as far as the machine construction is concerned. Does anyone else have experience with this 'safety at work' system? What are the pros and cons? Does the labor savings offset the material cost?
 
ASi safe wouldn't be my first choice - I'm NOT a fan.

I had my fingers burnt by by being an early adopter of ASi safe some years ago and although V3 of of the ASi monitor is much improved the system still has some drawbacks. E.G. I've recently changed out some old Siemens Laser Scanners for newer Sick models. This required reprogramming of the S7 PLC hardware config for the ASi master followed by reprogramming of the ASi safe application to "re-learn" the codes from the new slave.

Using ASi can simplify your installation but for a large system I would use Profi-safe and for a smaller system I would use a Pilz PNOZ Multi system.

Don't just take my word for it, I look forward to hearing about other peoples experiences.

Nick
 
I evaluated AS-i once, as a possible candidate for our bigger projects, with a view to using the safety as well.
It fell out of our favor partly because it cannot provide big enough networks with enough i/o for our purpose.
But if it had been big enough, then I believe it would have saved both time and expense, a lot of expense actually, when compared against traditional safety in a large plant.

For a smaller machine, I agree that AS-i is not the solution, because the biggest advantage is in replacing traditional cabling.

Btw whats with that avatar of yours !!?? Looks better now.
 
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I have used it on quite a few projects, i like it, projects were successful and i'd definitely use it again

Some things i found

You really need an S7 300 Cpu with an ASI Master to properly diagnose the Asi safety monitors/bus ( I am talking a siemens job here only as i haven't used other makes ). Siemens state the 200 can do this - Its not easy and doesn't work very well, the 1200 doesn't support ASi directly either.

The safety at work software is really quite easy for setting up the ASi Safety Monitor/s

As said above limited to the number of nodes, 64 from memory

And one thing i dislike is if the ASi Safety monitor fails (siemens ones) then you have to fit a new and go through all the teach and setup again, would be better if this was stored on an eeprom or card that can be unplugged and plugged into a new unit by maintenance

The plus side is the site time in wiring, saves a lot of time just running out the yellow and/or black asi cable rather than hardwiring every safety device. Erm does the labour saving off set the ASi cost - In the jobs i have done thats a definate yes. All the jobs i have done had digital IO, Analogue IO and Safety IO on the same ASi network. Length isnt really a problem if you use repeaters and extenders with an end terminator, although if you stick to the standard 50m (FROM MEMORY !) then none of that is needed

If you havent done ASi before and are proficient then read the manuals and all the info on the ASi sites, if your arent proficient then take a siemens course, they are pretty good.

http://as-interface.net/

http://www.as-interface.co.uk/

http://www.automation.siemens.co.uk/main/business groups/communications/asi/

If you get into ASi then invest in the ASi sniffer (Siemens and others do it) and a decent node setup and diagnostic device, i think mine the gossenmetrawatt one and its far better than any others i have had the pleasure in using

And as mentioned above i also use the sick safety lasers with the associated sick asi safety node - very very nice kit and software for the lasers is free
 
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The controller will be a Siemens S7-300 series PLC with an IFM Efector AC1335 Profibus to ASi Gateway.

Check with IFM that you can GATHER and DIAGNOSE ALL data from the safety monitors - what safety monitors are you using, i presume siemens ?

Why not just use the S7300 ASi Master ?
 
I'm not sure which safety monitor we will be using. I'm leaning more toward IFM because our local distributor is much more helpful than our Siemens distributor. As far as the Asi Master, I was planning on using the IFM Gateway to keep the machine as similar as possible to several other machines we have. (got to keep our maintenance department happy). But if the Siemens ASi master is as good as everyone is telling me then maybe I will consider it. I will read up on it today.
My real concern is whether or not the ASi 'safety at work' system is worth while. If we factor in the maintenance department aspect, I would have to say no. I just don't see the average maintenance department being able to troubleshoot and maintain an unusual system such as this. I will keep the normal ASi I/O and use conventional safety relays instead of the ASi 'Safety at Work' system.
 
If the jobs done correctly and everything on the asi including safety is on an hmi then its easier for maintenance

ie Node4 Failed - Replace

Maintenance replace and with a single node failure if its replaced with the same node (but a good un) then the asi master will program the nodes address

Diagnosis on estops and safety gates is also easier if programmed correctly

The ASi safety monitor has 3/4 leds on it and this can also be diagnosed on the HMI
 
Diagnosis on estops and safety gates is also easier if programmed correctly

The ASi safety monitor has 3/4 leds on it and this can also be diagnosed on the HMI

One of the early problems that I experienced with the ASi monitors (gate switches actually) was that all LEDs on the monitor showed OK but the system could not be reset. It was only posible to diagnose the error by an engineer with a laptop showing that a monitor was in fault even though all the LEDs and the feedback to the HMI said it was OK. As it was a 6000KM round trip to the customer and repeated visits were made, I've never trusted the system since.

Even today, one OEM customer of mine has recently ditched ASi safe.

Nick
 
One of the early problems that I experienced with the ASi monitors (gate switches actually) was that all LEDs on the monitor showed OK but the system could not be reset. It was only posible to diagnose the error by an engineer with a laptop showing that a monitor was in fault even though all the LEDs and the feedback to the HMI said it was OK. As it was a 6000KM round trip to the customer and repeated visits were made, I've never trusted the system since.

Even today, one OEM customer of mine has recently ditched ASi safe.

Nick

Must have been old f/w or just the early days ?

All the systems i have installed (all siemens with a little bit of sick lasers) have been excellent, any safety trips leds show red and all can be diagnosed on HMI
 
Be sure that your asi-monitor can report which input that tripped it. Had a ripple contact some years ago which was "impossible" to find.
Kalle

The Siemens ASi safety monitor can be programmed using a buffer to remember the last trips that faulted it. These would also be displayed on a HMI.
 

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