SM332 Analogue Output Card - Hot Swap

[leem2209]

Hello all,

Just looking into a little error on a valve in our plant, the valve isn't reacting to signals. The DCS is calling for the valve to move but no reaction. Give a simulated 4-20mA signal onto the valve controller and it responds... checked the analogue output from the SM332 card and zilch, nada, nothing.

Dodgy SM332 card... now I've been told that these are hot-swappable and Siemens info confirms:

"When used in the ET 200M distributed I/O system together with active bus modules, hot swapping of the digital input/output modules is possible without any reaction. The remaining modules continue to operate."
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As the plant runs continuously I don't have the luxury of doing a power down replacement. Looking at what will be affected during the swap, there's 6 out of 8 outputs used on this card, and hopefully that is all that would be affected. But, as these are all on a Backplane Bus, surely removing this would cut out all the analogue cards connected after it? There's approx. 5 more cards connected on the rack after this one... that's a lot of systems to loose.

Just after as much info before I do anything as we may have to schedule a plant stoppage in order to change. But if we can get away with a hot-swap then that would be great!

 

[sigmadelta]

Do you know if you are using the active backplane or not?

If your mounting rail looks exactly like an S7-300 then you are not. if the rail looks like it has plastic inserts in it, then you are.

This is what it looks like underneath

:https://proelektro.eu/att/large/0/86/73.jpg

OB 82 and OB 83 must be in your program as well.

 

[leem2209]

Ah.... I see! I'll go and double check! I was just thinking of the standard little linking thingies...! Thanks SigmaDelta....

 

[leem2209]

Yes we are using an active backplane! So I can happily hot swap the Analogue card and only lose the 6 outputs on that card?

 

[sigmadelta]

Which CPU do you have? Does it have program blocks OB86, OB82 and OB83 in the program?

 

[sigmadelta]

hmmm, there is more than I thought to your situation.

https://support.industry.siemens.com/cs/document/1826766/how-do-you-configure-the-change-module-during-operation-and-the-remove-plug-alarm-functions-in-an-et-200m?dti=0&lc=en-WW

The feature must be enabled in your hardware configuration under the properties of your IM 153-1 (as of 6ES7153-1AA02-0AA0 or later) or IM 153-2 module. The above link contains a screenshot of the IM 153 module settings.
AND the OBs (82, 83, 86) should be loaded in your program as well.

 

[boneless]

perhaps the only thing you need is a galvanic isolator to "boost" your signal? I have had devices having trouble to run directly off an analogue output before.

 

[leem2209]

I'll check all these things tomorrow when I'm back on site.

Our CHP plant is continuous 24/7 - 365 running so we have a lot of systems in place that allows us to do work on the run. Our DCS has dual-redundancy PLC's and I'm pretty certain that the design of the system allows the IO modules to be swapped on the run.

As for the boost, boneless, it's simply a PLC output and short run to the valve. This has been in operation for ten years now. A simulates 4-20mA signal onto the output cables operated the valve and output measured from the output module is zilch.