Yokogawa In-Situ Gas Analyzer TDLS200 - Manual (Page 32)

4-12 4-13
IM 11Y01B01-01E-A 6th Edition :Feb 13, 2013-00
<4. ANALYZER COMPONENTS>
RIU Optional Ethernet Switch
If there is more than one analyzer connected to the RIU, then they are routed via an industrial Ethernet switch.
Up to four analyzers can be routed through one RIU switch. The switch is powered by 24VDC from the
back-plane and includes several status LEDs.
RIU Optional Feed-through Board
To facilitate the connection of more than one analyzer to the RIU, an optional Feed-through board can be used.
The board has pluggable screw terminals that allow for the landing of field cables from the analyzers at the RIU.
RIU Hazardous Area Purging
The standard RIU is designed for operation in Safe Areas (General Purpose). An optional Z-Type purge control
system can be fitted to the RIU and it includes a local indicator and pressure switch alarm contacts. When
applied, the purge system allows for operation in:-
• NEC/CSA Class 1, Division 2, Groups A-D
• ATEX Zone 2 CAT 3 (dual regulators at the inlet MUST be used)
The purge gas may be either Instrument Air or Nitrogen.
4.9 Purge Systems
The TDLS200 Analyzer requires a continuous nitrogen gas purge to prevent ambient oxygen ingress to the opti-
cal path, when oxygen is the measured gas. The flow rate can be minimized as long as it prevents any ambient
oxygen ingress to the measurement optical path. Other purge gases may be used as long as they do not contain
any of the measured gas and they are clean, dry, etc.
For hazardous area operation, the same nitrogen purge gas is used to purge the entire analyzer (including
non-optical path sections such as the electronics). The process interface may also require purging to maintain
clear windows, refer to Process Window Purge details separately.
TDLS200 TDL Analyzer Instruction Manual V2.1
Page 33 of 131 - 33 -
RIU Optional Ethernet Switch
If there is more than one analyzer connected to the RIU, then they are routed via an industrial
Ethernet switch. Up to four analyzers can be routed through one RIU switch. The switch is
powered by 24VDC from the back-plane and includes several status LEDs.
Figure 11 - RIU Ethernet Switch
RIU Optional Feed-through Board
To facilitate the connection of more than one analyzer to the RIU, an optional Feed-through board
can be used. The board has pluggable screw terminals that allow for the landing of field cables
from the analyzers at the RIU.
RIU Hazardous Area Purging
The standard RIU is designed for operation in Safe Areas (General Purpose).
An optional Z-Type purge control system can be fitted to the RIU and it includes a local indicator
and pressure switch alarm contacts. When applied, the purge system allows for operation in:-
ƒ Z-Purged or X-Purge designed in accordance with NEC/CSA Class 1, Division 2, Groups
A-D NEC/CSA Class 1, Division 2, Groups A-D
ƒ Certified ATEX Zone 2 CAT 3 (dual regulators at the inlet MUST be used)
The purge gas may be either Instrument Air or Nitrogen.
2.3.10 Purge Systems
The TDLS200 Analyzer requires a continuous nitrogen gas purge to prevent ambient oxygen
ingress to the optical path, when oxygen is the measured gas. The flow rate can be minimized as
long as it prevents any ambient oxygen ingress to the measurement optical path. Other purge
gases may be used as long as they do not contain any of the measured gas and a clean, dry, etc.
For hazardous area operation, the same nitrogen purge gas is used to purge the entire analyzer
(including non-optical path sections such as the electronics). The process interface may also
require purging to maintain clear windows, refer to Process Window Purge details separately.
Analyzer 1
SBC
Analyzer TB6
Tx Tx Rc Rc
Ethernet
Switch
Feed-through
Board
Tx Tx Rc
Analyzer 2
SBC
Analyzer TB6
Tx Tx Rc Rc
RIU
SBC
Feed-
Through
Board
Figure 16 – RIU Ethernet Switch