GE PACSystems RX3i User Manual page 40

Glossary, continued
PNC
PROFINET Controller: Typically, the generic PROFINET Controller function. PNC001 represents a
slot-mounted product (IC695PNC001). Embedded PROFINET Controllers may be configured on
LAN2 for CPE400, CPE330 and CPE100/CPE115. Both embedded and slot-mounted perform the
same functions on the PROFINET network, but there are differences to be noted in installation,
configuration, operation and performance.
PNS
PROFINET Scanner. Head-end module that controls I/O in rack and communicates with PROFINET
network. Both RX3i (IC695PNS001) and VersaMax (IC200PNS001, IC200PNS002) modules are
discussed in this manual.
PNSR
PROFINET System Redundancy: the PROFINET processes and mechanisms by which an IO-Device
is controlled by multiple IOCs in redundant PLCs.
RDO
Record Data Object. Services used to read and write structured data stored in a PROFINET IO-
Device.
Reduction Ratio
Along with Send Clock determines the Update Period for a PROFINET cyclic data transfer between
two devices (see IOCR). The Update Period equals the Reduction Ratio multiplied by the Send Clock
time. For example, if the Reduction Ratio is 4 and the Send Clock is 1ms, the Update Period is 4ms.
Remote Node
For an RX3i PROFINET network, a Remote Node is any PROFINET IO-Device, such as a rack of I/O
modules with a Remote Scanner or a third party PROFINET IO-Device.
RIV
Reference ID Variables
RTA
Real-Time Acyclic. A PROFINET-IO Mechanism used to exchange non-periodic data such as alarms.
RTC
Real-Time Cyclic. A PROFINET-IO Mechanism used to exchange input and output data.
Send Clock
Value between 1 and 128 inclusive in units of 31.25 µs (equivalent to a range of 31.25 µs to 4 ms)
used to calculate the Update Period for a PROFINET cyclic data transfer between two devices (see
IOCR). The Send Clock is the basis for all other scheduling parameters.
Send Offset
The time to delay a scheduled PROFINET cyclic data transfer frame.
Measured in nanoseconds from 0 to 3,999,999. Must be less than the Send Clock time.
SFP
Small Form-factor Pluggable. Pluggable, hot-swappable transceivers.
SNMP
Simple Network Management Protocol. UDP-based network protocol that facilitates the exchange
of management information between network devices.
Status Bits
Module status data in RX3i CPU reference memory.
Submodule
PROFINET-IO representation of the smallest configurable entity of a PROFINET Module.
SVC_REQ
Service Request Function Block. A control system service initiated by the RX3i CPU.
TLV
Type-Length-Value
Unicast
In Ethernet, the transmission of a network message to an individual host.
Update Period
The time between PROFINET cyclic data transfers between an IO-Controller and an IO-Device.
USB
Universal Serial Bus
WinLoader
A software utility used to download and install firmware upgrades via a serial port.
GFK-2571N May 2018
Chapter 1. Introduction
29