Chevron was upgrading their truck load-out facilities on Pocatello, ID, Boise,
ID and Pasco, WA. They came to me to upgrade their local process communications
and find a way to communicate the data to a central office in Tucson, AZ.
I visited each facility and talked with the manager. We worked together to find
out exactly what were the problems facing them and what were their future needs.
After the visits and talking with manufacture of the new control system software
that was being installed as part of the upgrade it was decided that fiber optics
would be an integral part of each communications network. Fiber optics were used
not for speed but to optically isolate different systems parts from lightning
strikes. It was also decided that the network would be TCP/IP based for ease of
communicating with the central office. The trick was finding a way to get all
the serial data in the plant into something that could be transported across
TCP/IP. We settled on the Equinox ESP-8 MI units that take incoming RS-485,
RS-422 and RS-232 serial data and 'wrappers' it in a TCP/IP packet that then can
be sent any place in the world. I installed Cisco routers at each facility to
give Tucson access to each local LAN via a T1 connection. Drawings
the communication block diagram for each facility.
Photo1 is a finished panel
except for installing the fiber optic patch cords. This panel also includes
eight optically isolated protocol converters to further protect the BlenkPaks at
Pocatello. In Boise one panel had to be retrofitted in the field.
that panel with that work in progress. I have included a completed
drawing package for the Pocatello Facility.
Photo-DEU is of the finished Driver
Diagram 1 (.pdf )
Communications Block Diagram 2 (.pdf )
Communications Block Diagram 3 (.pdf )
Drawing Package (.pdf 795k)
Driver Entry Unit (.jpg)