ROC827 Instruction Manual

P, Q (continued)

 

 

P/DP

Pressure/Differential Pressure.

PI

Pulse Input.

PID

Proportional, Integral, and Derivative control feedback action.

PIT

Periodic Timer Interrupt.

PLC

Programmable Logic Controller.

Point

Software-oriented term for an I/O channel or some other function, such as a flow

 

calculation. Points are defined by a collection of parameters.

Point Number

The physical location of an I/O point (module slot and channel) as installed in the ROC.

Point Type

Defines the database point to be a specific type of point available to the system. The

 

point type determines the basic functions of a point.

Preset

Number value previously determined for a register.

PRI

Primary PID control loop.

Protocol

A set of standards that enables communication or file transfers between two computers.

 

Protocol parameters include baud rate, parity, data bits, stop bit, and the type of duplex.

PSTN

Public Switched Telephone Network.

PT

Process Temperature.

PTT

Push-to-Talk signal.

Pulse

Transient variation of a signal whose value is normally constant.

Pulse Interface

A module that provides line pressure, auxiliary pressure, and pulse counts to a ROC.

module

 

 

PV

Process Variable or Process Value.

R

 

 

Rack

A row of slots on a ROC into which I/O modules can be plugged. Racks are given a letter

 

to physically identify the location of an I/O channel (such as “A” for the first rack). Built-in

 

I/O channels are assigned a rack identifier of “A” while diagnostic I/O channels are

 

considered to be in “E” rack.

RAM

Random Access Memory. RAM is used to store history, data, most user programs, and

 

additional configuration data.

RBX

Report-by-exception. RBX always refers to Spontaneous RBX in which the ROC contacts

 

the host to report an alarm condition.

RR

Results Register; stores the Signal Value Analog (SVA).

RFI

Radio Frequency Interference.

RI

Ring Indicator modem communications signal.

ROC

Remote Operations Controller microprocessor-based unit that provides remote

 

monitoring and control.

ROCLINK 800

Microsoft® Windows®-based software used to configure functionality in ROC units.

ROM

Read-only memory. Typically used to store firmware. Flash memory.

Rotary Meter

A positive displacement meter used to measure flow rate, also known as a Roots meter.

RTC

Real-Time Clock.

RTD

Resistance Temperature Detector.

RTS

Ready to Send modem communications signal.

RTU

Remote Terminal Unit.

RTV

Room Temperature Vulcanizing, typically a sealant or caulk such as silicon rubber.

Issued Mar-06

Glossary

A-6

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Emerson ROC827 instruction manual Point Type, Preset, Protocol, Pulse Interface, Rack, Rotary Meter