Can I install 2 Processors on one rack?

Hi There,

I am wondering if i can install 2 Processors (Compact Logix)on one rack. The purpose to doing this is because we need put a back-up PLC into the control panel. If 2 processors are able to install on one rack, we will save some space and expense in our control panel. Are there anyone did this before?

Thanks,

Robin

Yes, you can install 2 processors in one rack, but that is NOT how you want to do a redundant system.

Thanks OZEE. Please expain more detail.

Hi Ozee,

Thank you for your reply. I guess i asked a wrong question.

I want to have 2 processors (Compact Logic) install side by side (data cable connected) and configure these 2 processors as a hot-standby system.

May i configure like above description? If it works, are there any special requirement?

Thanks a lot,

Robin

No. Not with CompactLogix - one processor per chassis

Yes. With ControlLogix - any which way

But redundancy (hot back-up) goes way deeper than that

You are considering using redundant processors, but what about redundant chassis, redundant power supplies, redundant I/O, redundant cabling, etc. etc.

we will save some space and expense in our control panel.

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Space and expense should be secondary considerations when designing a redundancy system. Think about why you are considering "redundancy", and apply it across the board if it makes sense.

i always read about redundancy but i am not sure what does it exactly mean.Is it like having backup if one fails or something else? Sorry for asking a stupid question

Oops -- read that as ControlLogix, not Compact...

Daba's right - can't do it at all with Compact.

bornwild said:

i always read about redundancy but i am not sure what does it exactly mean.Is it like having backup if one fails or something else? Sorry for asking a stupid question

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Bit of a drift off main topic but good question.

Redundancy is having a backup. Very commonly used on aircraft submarines, hospitals, where systems MUST work to ensure life safety.

In those cases they were often a complete duplicate installation where either A or B could carry the load. Examples lighting two normal AC lighting and two backups (one off main battery and one that was individual lanterns.

Two hydraulic pumps either one could carry average load backed up by other and then backed up by larger pumps (Main and Vital).

At home - a generator to provide power in case of utility failure.
Dan Bentler

Just as a quick side note, the oil and the gas industries sometimes use triple and quadruple redundancy

MarkNightingale said:

Just as a quick side note, the oil and the gas industries sometimes use triple and quadruple redundancy

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Apparently not BP last summer.


rpoet