ROC364 Instruction Manual
G-4 Glossary Rev Jun/05
Ohms – Units of electrical resistance.
On-line – Accomplished while connected (by a communications link) to the target device. For example,
on-line configuration is configuring a ROC while connected to it, so that current parameter values
are viewed and new values can be loaded immediately.
Opcode – Type of message protocol used by the ROC to communicate with ROCLINK configuration
software, as well as host computers with ROC driver software.
Operator Interface – Local Operator Interface (LOI) refers to the serial EIA-232 (RS-232) port on the
ROC through which local communications are established, typically for configuration software
running on a PC.
P, Q
Parameter – A property of a point that typically can be configured or set by the user. For example, the
Point Tag ID is a parameter of an Analog Input point. Parameters are normally edited by using
ROCLINK configuration software running on a PC.
Pf – Flowing pressure.
PC – Personal computer.
PI – Pulse Input.
PID – Proportional, Integral, and Derivative feedback loop control action.
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 rack and number of an I/O point as installed in the ROC system.
PRI – Primary PID control loop.
Protocol – A set of standards that enables communication or file transfers between two computers.
PSTN – Public switched telephone network.
PT – Process Temperature.
PTT – Push-to-talk signal.
Pulse – Transient variation of a signal whose value is normally constant.
PV – Process Variable.
R
Rack – For a ROC, a rack is a row of slots into which I/O modules may be plugged. The rack is given a
letter to physically identify an I/O channel location, 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
rack “E”.
RAM – Random Access Memory. In a ROC, it is used to store history, data, most user programs, and
additional configuration data.
RBX – Report-by-Exception. In a ROC, it always refers to Spontaneous RBX in which the ROC
contacts the host to report an alarm condition.
RFI – Radio frequency interference.
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