Hi all,

Because of lack of maintenance and operational problems (Aluminum Hydrate Spillage), our plant is required to replace a lot of terminal boxes (TBXs) together with multiconductor cables that connect conventional field instruments (4-20 mA output) to Honeywell TPS control system in cable rooms. The problem is similar for digital signals that go to different locations (wiring exchange cabinets connecting to Simatic S5 extension controllers) within the plant. The maximum distance is approximately 600 meters long.

My task now is to evaluate different technologies on the market that may conduct us to decide what the best solution would be to replace those deteriorated terminal boxes and cables by using the minimal number of conductors from the field, where instruments are located, to the cable rooms, and causing the minimum operational traumatisation during the migration. Our main concern is the multiconductor (multipair) cable.

At this time I am considering multiplexing techniques over optic fiber and also wireless communications (ISA SP100), but we are open to hear any suggestion from you. I would like to hear about technologies, techniques, products and experiences.

Of course, we are also considering migrating from Simatic S5 to S7, from Honeywell TPS to Experion system and progressively from conventional to intelligent instruments.

Any suggestions? Your help and comments would be appreciated.

Thanks.

Mario Perez

 

It seems as though you need some sort of distributed I/O system (assuming you don't want to replace your 4-20 instruments). What options does your control system offer?

I couldn't understand why your multicore cables need replacing, what is damaging those?

Lack of maintenance now so I assume lack of maintenance in the future.

You are looking to change to some sort of fieldbus in the future so perhaps consider using the control options built into the instruments to distribute the control out into the field with fiber back to the control room.
Is your plant one big integrated process or a number of cells?

Sounds like you have quite a task.

Roy