Architecture Queries Micrologix 1400

Hi All,

I am having an water level control application. This Apartment have 4 buildings, each building have 2 Tank, so total 8 tanks. Each tanks have 6 limit switch (including redundant), so there are 8*6=48 Limit switches.All 4 buildings are 21 storey. PLC is located at basement. Can i have one I/O module(1762 MICROLOGIX EXPANSION I/O) at top of the building, where i can connect all limit switches and then connect this I/O module to the PLC(processor) at basement? Hope this is the so called Remote I/O concept...

Is there any better architecture?

I am not sure if you can use remote I/O with a Micro Logic PLC as I have never tried it. I do know that the 1762 I/O is designed for use local to the PLC and is not designed for use as Remote I/O.

Remote I/O: 1734 Point I/O or 1794 Flex I/O.

With the building being 21 Stories connection between a PLC in the basement and a remote rack on the roof is going to be problematic. You may be better off looking at installing 2 PLCs and having them talk ethernet i/p with some ethernet switches between them. I do not have the exact distance spec but I would guess you would need atleast 2 switches for that distance.

RANDHEER, clay is right. fiber would work though. my question is why could you not just put the plc on yhe roof also? and I have never seen limit switches work with water are you sure you don,t mean levelswitches? I try and use pressure transducers for level/pressure when dealing with water.

The scenario you have doesn't really suit a MicroLogix in all fairness.

You could really do with a CompactLogix system and then Point I/O via EtherNet I/P nearest the central cable gathering location. Depending on distance, you may need intermediate switches as the other chaps have said.

You really need to re-assess equipment capability versus hard wired signal locations.

Thanks all,

@Clay: The budget won't allow us to go for 2 PLCs. But I'm interested to know which is the lowest model AB PLC where I can use 1734 Point I/O or 1794 Flex I/O.

@bce123: Yae sorry, Level Switches. Customer won't allow to Place PLC on Roof top, he want it near control panel which is in basement and more over when compared, one building is bit far.

@Chris: You are right,we need CompactLogix system but budget for a water level automation is...

In this situation some are suggesting to wire down from roof top to basement with 46 level sensors, using multi core wires. I can't even think about this bulk wiring. Any small memory devices is there which I can combine with Micrologix 1400? Or is multiple lowlevel (than micrologix) devices that can be used in this scenario.

I think the tidiest method would be to get all the sensors together, say at the top of the building in a marshalling box. Then install a good multicore cabling system from the top to the bottom.

Its a lot of wiring, but if you are into it, you wont walk away without it being as much artwork as good engineering.

RANDHEER, what is the total distance between the basement and the tanks the cost of the 1 ml1100 2 input cards and 1 c-more 6" hmi with e-net and web/email trending/alarms which could be mounted in the basement for control, leaving the ml1100 on the roof incase of e-net failure would be a good soultion for around $2100.00 us

Thanks a lot Mr.Chris and Mr.bce for your valuable suggestions...........

Welcome!

All the best and good luck with the project!

Let us know how it goes! The only way to learn is by others teaching who have been there and done that.

Sure....