In 1979, the DCU had a default module mix that provided good continuous control._ This software and hardware combination was called an Analog Control Unit._ So in 1979 someone could say they have a DCU1000 or they could say they have an ACU. _ Both were equivalent. Then in 1980 Fischer & Porter developed newer modules that would do Batch control and other discrete control logic._ They called this hardware / software combination a Multifunction Control Unit or MCU since it could do continuous control as well as batch control._ So they had a DCU1000 that could be an ACU flavor or an MCU flavor.

Also to come out in the DCI-4000 product line was two types of boxes that would sit between the DCU1000 and the CTBs. They would allow for manual control of the plant. Basically they were just switches and potentiometers (pots). The one for analog control was called a ABU (Analog Backup Unit) and the one for Descrete (on/off) Control was called a Contact Backup Unit (CBU).

Review:
DCU1000: Distributed Control Unit 1000
ACU: Analog Control Unit
MCU: Multifunction Control Unit
Controlware: The software that did the actual control using software blocks called modules.
ABU: Analog Backup Unit
CBU: Contact Backup Unit

The operator Screen was called a Local Operator's Panel (LOP)(pronounced "el oh pee")._ Lets look at all of these words one at a time._ The word Local means that the LOP was connected directly to the DCU1000 using a serial port._ The word Operator means that this was primarily used for controlling and monitoring the plant. (versus Configuring the system)._ And the word Panel is important too, because this CRT was to replace the old traditional panel in the control room._ This meant that instead of seeing individual controllers on the wall, the operator would see graphical representations of those controllers on the screen.

How did one configure the modules in a DCU?_ Answer:They used a silver box with a keypad and a reel to reel digital tape. The box was silver metal on the outside and it had a handle. It was like a small suitcase or large briefcase. This box (also known as the "silver bullet") connected to a port on the LOP and was able to configure the DCU1000.

This is all probably more information about DCI-4000 than you want to know, but there were a few more products.

The printer that was used was an Anadex model. This connected directly to the LOP. It printed out Alarms that came from the DCU and Logs / reports that came from a special DCU Controlware Module called a LOG module.

The early I/O wiring connections used a Customer Termination Board or CTB. The field wiring came into the cabinet and was attached to screw terminations on the CTB. Then, special amp connectors were used to route 8 inputs / outputs at a time to the back plane of the DCU, where the internal wiring of the backplane would route the signal to the appropriate I/O board in the DCU.

In Living Color

In Living Color II

Also during this time period, there was a need for getting data to the outside world (even as today!). So, about 1982/1983 a machine was designed based on a DEC 11/23 computer to store and forward information from the DCI-4000 system to "any" other computer. But mostly data would be sent to a Third-party VAX computer. This machine/product was called a Store and Forward Teminal or SFT. It was never a very popular product becuase it would hang sometimes and not send data.

Time Marches On

The very first few DCU2000 units were 1A highway compatible. In this way, an existing customer who had a DCU1000 could upgrade to a DCU2000 with not one other change.
Also in 1985, the COP was changed to a newer processor and the Distributed Operator's Console (DOC) (Pronounced "doc") was born. The DOC was ETHERNET based which meant that the DCU2000 had to be upgraded to ETHERNET also. This was done, and only a handful of DCU2000 1A Highway compatible units ever shipped. They were all upgraded to ETHERNET versions.

In 1986 a super new version of the LOC came out called LOC2000. In fact, the LOC2000 had three versions: LOC2000, LOC2500 and LOC2800. Also, a new board for the DCU2000 came out called an ICOM/X board. This board could communicate to PLCs and Micro-DCI. In other words, more changes were comming.
The person who came up with DCI-SYSTEM either was swayed or left because around this time the product name was changed again to DCI-5000.

DCI-5000

It was a nice little product line at the time.

One of the major problems with this arrangement, however, was that the LOC was configured completely differently than the DOC. That meant different graphic tools, different log tools, different everything.
The good part was that the LOC was a very robust machine. It hardly ever failed. Also it could be connected to a DCU1000 or a DCU2000 seamlessly!
The DOC could only be connected to a DCU2000 running Ethernet. As far as the Store & Forward Terminal (SFT) was concerned it was dead as a machine and was transformed into a circuit board that would fit into a VAX computer. The SFT board did the same function as an SFT machine but of course it was smaller and somewhat less expensive. Again though not too many sites had this product.

Time Marches On Again

But in reality, the product line was getting old. Controlware had only changed once since 1979 (and that change was very minor -- having to do with the way DCU2000 addressed I/O boards versus the way DCU1000s addressed I/O boards.
A new product line was on the way...