Rockwell Automation 1797-XXX FLEX Ex System Certification Reference Manual - Manual (Page 97)

Publication 1797-6.5.6 - June 2005
ControlNet Ex System 21-3
Describing the ControlNet
Ex System Diagram A maximum of 48 ControlNet Ex TM nodes may be connected together by
250m of coax cable and 48 taps. The distance increases to 1000m when you
use only 2 taps. See the table below for more information.
The fiber media of the 1797-RPFM can be installed in a hazardous location
(Class I, Zones 0, 1, and 2; Class I, Division 1 and 2; Class II, Division 1 and 2;
Class III, Division 1 and 2) to connect two 1797-RPFM modules or they can
be installed through different locations into the non-hazardous location to
connect the 1797-RPFM with any approved associated apparatus.
All cables and fiber media that are not light blue must be marked as IS using
the 1797-EXMK marking kit or other locally approved IS identification
and/or segregation method.
During the installation of the ControlNet Ex system, all metallic parts must be
isolated to prevent an earth connection (high voltage withstanding of isolating
material must be > 500V ac).
System
Diagram
Name Catalog Number Catalog Name Description
1797-RPA 1797-RPA ControlNet Ex Modular
Repeater Adapter Represents one ControlNet Ex node and
must be connected to a coax trunk cable
by
1797-TPx
1797-RPFM 1797-RPFM ControlNet Ex Fiber
Repeater Module,
Medium Distance Allows connection of a maximum of two
devices per 1797-RPA and is powered
directly by 1797-RPA
1797-ACNR15 1797-ACNR15 Redundant Media
ControlNet Ex Adapter Represents one ControlNet Ex node and
must be connected to a coax trunk cable
by
1797-TPx -each one with two redundant
output channels that are connected to
different ControlNet Ex networks (coax
cables and 1797-TPx)
CNet Ex
Tap Trm 1797-TCAP ControlNet Ex Tap
(Dummy) Terminator Represents one ControlNet Ex node and is
a simple capacitor (56pF) with a coax
connector
ControlNet Ex
Tap 1797-TPx ControlNet Ex Coax
Tap Four types of connections available: S
(straight t-tap), R (right angle t-tap), YS
(straight y-tap), and YR (right angle y-tap)
- a maximum of 48 taps can be connected
together by coax trunk cable
CNet Ex
Trk Trm 1797-XT ControlNet Ex Trunk
Terminator Simple resistor (75
Ω) with coax connector
that must be on each end of the ControlNet
Ex coax trunk for termination
Coax Trunk
Cable 1797-RG6 Quad-Shield, RG-6
75
Ω Coax Trunk Cable
Maximum (functional) length between 2
1797-TPx is 3280ft (1000m) - each
1797-TPx reduces the (functional) coax
cable length by 53.4ft (16.3m)
None None Standard Coax Trunk
Cable BNC Couplers Different standard cable couplers, 90 o ,
180 o , etc.