4-slot Chassis

If you have a 4-slot chassis for controllogix and you install 4 1756-ENBT cards with NO processor. Would the first ENBT card be in slot 1 or slot 0

I think 00 or just 0 then 1,2 and 3

The left-most slot of a ControlLogix chassis is always considered Slot 0, no matter what kind of module is installed in it.

Why

Prayder said:

If you have a 4-slot chassis for controllogix and you install 4 1756-ENBT cards with NO processor. Would the first ENBT card be in slot 1 or slot 0

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What is the purpose of such a configuration ?

passwordg said:

What is the purpose of such a configuration ?

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Several but one is a bridge network, the CLX rack and cards make great communication bridges when you have several networks in the same building

Years ago I worked for a company that had about 10 different DH+ networks and this was a reliable way to easily move them to Ethernet

Prayder said:

If you have a 4-slot chassis for controllogix and you install 4 1756-ENBT cards with NO processor. Would the first ENBT card be in slot 1 or slot 0

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Prayder, the slots in the chassis are just that, slots in the chassis. They are numbered from 0 to n, from left to right.

0 to 3 in a 4-slot chassis
0 to 6 in a 7-slot chassis
0 to 9 in a 10-slot chassis
0 to 12 in a 13-slot chassis
and
0 to 16 in a 17-slot chassis

There is absolutely no restriction on module placement, a controller does not have to be in slot 0, and you can put any ControlLogix (or third party) module in any slot. Placing a controller module in slot 0, for example, does not change the slot numbering in any way - the slots are the slots, regardless of what module is put in them.

The chassis backplane (aka "ControlBus") is an active network component, and the "node address" of a module is its slot number in the chassis.

daba said:

There is absolutely no restriction on module placement, a controller does not have to be in slot 0, and you can put any ControlLogix (or third party) module in any slot. Placing a controller module in slot 0, for example, does not change the slot numbering in any way - the slots are the slots, regardless of what module is put in them.

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True until you get to the Guardlogix and the safety partner is required to be in the next slot. Got bit by that many moons ago.

jstolaruk said:

True until you get to the Guardlogix and the safety partner is required to be in the next slot. Got bit by that many moons ago.

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I did say ControlLogix, and didn't want to muddy any waters.

I can't think of any restrictions like a module needing to be less than so many slots away from the power supply either, a restriction that does exist in Compactlogix.

daba said:

I did say ControlLogix, and didn't want to muddy any waters.

I can't think of any restrictions like a module needing to be less than so many slots away from the power supply either, a restriction that does exist in Compactlogix.

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Guardlogix is listed as a "sub-brand" in the ControlLogix 5570 family (as is the Controllogix-XT and Guardlogix-XT), that's why I pointed it out. In case someone thought they could just drop one in as a replacement for an upgrade.

jstolaruk said:

Guardlogix is listed as a "sub-brand" in the ControlLogix 5570 family (as is the Controllogix-XT and Guardlogix-XT), that's why I pointed it out. In case someone thought they could just drop one in as a replacement for an upgrade.

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None of this over-discussion helps the OP to understand that the chassis has n slots, numbered 0 to n-1. Nothing changes that, ever.

A GuardLogix controller will be in slot x, and its safety partner has to be in slot x+1. The redundancy system is built around that constraint, there is a lot of intercommunication between the two modules, which isn't programmable like it is in Messaging, or Produced/Consumed data transfer.

daba said:

There is absolutely no restriction on module placement, a controller does not have to be in slot 0, and you can put any ControlLogix (or third party) module in any slot. Placing a controller module in slot 0, for example, does not change the slot numbering in any way - the slots are the slots, regardless of what module is put in them.

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Then why reply with this explaination that was not entirely correct and according to you was not relevant?

Don't answer that, we're all human and allowed to be imperfect.

jstolaruk said:

Then why reply with this explaination that was not entirely correct and according to you was not relevant?

Don't answer that, we're all human and allowed to be imperfect.

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I will answer it...

I figured that since the OP wasn't sure about whether module placement changed slot numbers, he wasn't going to be working on a Safety PLC.

As I stated, not muddying waters, giving enough information to reply to his question, without adding too much "extra" information, which he may find out himself in due course, was the prime objective.

That's the way training works, especially at Rockwell. The only mention of GuardLogix on their Logix5000 basic course is in session 1, during a roundup of the various hardware platforms, but they don't go into detail about module placement at that point, it is way too early to introduce square pegs and round holes.

Everyone needs to make the minimum number of steps necessary on an ever-expanding ladder, to maintain balance at all times.

When all that "basic" information is safely filed away for future reference, and when faced with a GuardLogix system for the first time, that grounding makes the reading of the installation manual and GuardLogix documentation, (which is always recommended practice), so much easier to comprehend, and no need to count how many moons.

daba said:

I did say ControlLogix, and didn't want to muddy any waters.

I can't think of any restrictions like a module needing to be less than so many slots away from the power supply either, a restriction that does exist in Compactlogix.

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I know some of the motion and hydraulic modules have to be in the chassis with the processor and there is a max amount of them per chassis and per processor and it's a low number IMO on some of them IIRC.