Safety Device Net

Just received a leaflet from Omron re Safety Device Net. Have not had a chance to read about it yet.

Do other manufacturers have Safety Device Net?

Anyone with any experience with it yet?

Will post a bit more after I have time to read about it over the weekend.

Yes. Rockwell.
Only experience has been in labs etc.
Regards Alan Case

I heard this was in the pipeline a long time ago. Glad it's finally appeared.
I think ASi Safe was one of the biggest leaps forward in automation. Glad DeviceNet has caught up.

Glad DeviceNet has caught up.

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Jumped in front I believe due to the capabilities of D/Net as compared to the limited digital capabilities of ASI, although ASI does what it is designed to do very well. Asi handles limited analogue in a pretty messy way.

Sorry, Bob - to clarify; I meant ASi Safe (not ASi). DeviceNet is more capable, but has been missing this 'safety' element. That's what I meant by 'caught up'
Regards - Pp

I could be wrong as it's been a while since I've seen it, but I think Guardmaster have a safety net system. I beleive it's called guardshield or something along those lines.

A-B is coming with safety devicenet I/O for Guard PLC in a few weeks.
System will be based on Guard 1600 and 1800 PLCs with I/O connected via a high speed serial interface to a DeviceNet scanner.
Safety I/O modules 1791DS will operate on DeviceNet and can work along with regular (non safe) DNET I/O.
Later, same Devicenet I/O will be used with new GuardLogix controllers based on the ControlLogix platform.

That's the whole idea of Safety Devicenet. Multiple vendors. Interoperability. What a concept!

how about speed? i've seen profisafe etc. but dnet is rather slow
(even with top speed of 500kbps).

what kind of response time we are talking about if you have light curtain connected to dnet in one place and contactors that stop machine are in another...?

Still have not had time to have a good look. Maybe over the weekend.

panic mode said:

how about speed? i've seen profisafe etc. but dnet is rather slow
(even with top speed of 500kbps).

what kind of response time we are talking about if you have light curtain connected to dnet in one place and contactors that stop machine are in another...?

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From what I heard for small data size you can get RPIs within 10ms.

Finally had time to have a look.

On the front of the brochure is the claim "The Wolrd's First DeviceNet Safety Controller With Network Capabilities". Also, "Complies with the Highest Safety Standards in the World".

It appears that the system is based around EN 954-1 Safety Category 4 and IEC 61508 SIL 3. This is top level protection and where most good safety relays sit.

There is a Safety Network Controller with 16 safety inputs and 8 safety outputs. There are also Safety I/O terminals to hook into the network. The whole thing can then be hooked up to an existing Device Net network with the master PLC monitoring the safety network only - no control. Fair enough! The level of monitoring includes all the maintenance functions offered in the latest Device Net I/O systems.

There is a set of software required to set up the sfatey network. Programming is by pre-determined function blocks. One would assume that they are probably protected as they have probably had to go through a series of testing for functionality.

The mentioned testing authorities are TUV Rheinland and UL. Various standards and parts of standards are mentioned.

Interestingly enough, the Safety Network Controller has a USB port (USB1.1). The other method of communications to set up the controller is an interface card for your laptop. Cannot program the Safety Controller in a normal PLC as we do with normal D/Net I/O. I guess that makes sense as the unit is, and must be, a stand alone controller.

Will have to get the manual (Z905) and investigate further. The leaflet document number is Z907-E1-01 if anyone is interested.

There is no mention of scan and network communications times in the leaflet. There may be more in the manual.

Allen Bradley have just introduced the GuardLogix PLC based on the Controllogix. It uses a devicenet scanner and a special CPU and co-processor. The safety logic is programmed using a special version of logix 5000. The safety I/O is in the remote modules. It looks pretty good for large production line systems. I was considering it for a system with 7 conveyors with 4 e-stops per conveyor and some other machinery. Probably a total of 35 e-stops, stopping 10 motors.

One of the advantages over hard wiring is the diagnostics and the ability to safely use complex logic.

GuardLogix PLC based on the Controllogix

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It seems that this may be the next extension of safety without having to use a very expensive safety PLC. I have seen a little sketchy information but am waiting to see a rep. Will not comment further on that until I find out more.

I guess the advantage I see with the Omron idea is that it can be used on any brand of Device Net loop without going to the expense of a specialised processor to run the whole thing. Safety PLC's are very expensive. This appears to be a lower cost solution to the whole safety issue. The logic is in the Safety Network Controller only and the whole system can be monitored from a normal processor with a Device Net scanner. There can also be normal Device Net I/O modules on the same loop.

Interesting developments abound, possibly prompted by the ASI units, possibly just evolution and new products to sell. Good to see though.

Here is a link to safety cip spec from odva:
http://www.odva.org/10_2/cipsafety/docs/cipsafetywp_en.pdf

A-B has 2 different product line with safety devicenet:
- GuardLogix based on ControlLogix platform - to be released later this year or next year
- Guard PLC with DeviceNet scanner - will be released in a few weeks.

Both systems will be using same 1791DS I/O blocks.
GuardLogix will use 1756-DNB as a bridge only, all safey functions will be done by Guardlogix Processor L61S or L62S. DNB still can control standard I/O by mapping. Safety I/O will be in I/O configuration.