9
4.4.5 RS-485/4-20 mA cable Ferrite
To meet IEC requirements for RF radiated immunity a clamp-on type
ferrite is supplied in the accessory kit. It should be placed on the RS-
485 or 4-20 mA cable outside, as close as possible to the CLX-Ex. If
both outputs will be used, an additional ferrite will be needed and can
be ordered from HF scientific Catalog number 24560.
4.4.6 Modbus Control
In addition to the above mentioned Remote Standby Connections,
the same control can be achieved using Modbus control. Two special
Modbus addresses are provided.
The reading cycle is initiated using the coil 00005 with default at False
(0). Setting this address to True (1) initiates the reading cycle.
At any time the standby status can be check at Modbus Coil Address
00005 or Modbus Input Address 10005. False (0) indicates standby
and True (1) indicates the measurement cycle is taking place. Control is
only available from the Coil Address 00005.
4.5 Installing Reagents
The CLX-Ex will require that two reagents be installed
prior to operation. These are a buffer and an indicator. For
reagent preparation refer to section 11.2
Replacing and
Installing the Reagents.
5.0 Air Sentinel Controller Operation
The Air Sentinel controller is mounted on the side of the main enclosure.
This controller will ensure proper safe operation of the CLX-Ex. If of
all the required conditions are met, the controller will act as a power
governor. It does this by monitoring the pressurization of the main
enclosure with clean dry air. Should this air supply pressure fail the
PRESSURE
lamp on the Air Sentinel unit will turn RED and power to
the rest of the instrument is disconnected.
5.1 Start Up
When power is applied to the CLX-Ex for the first time,
ensure that the air supply is connected as stated in section
4.3 and the cabinet is closed and locked. Once power is
applied, the Air Sentinel will go through a purge period of
5 minutes where at least five volumes of the enclosure are
pushed through the CLX-Ex and out the Air Sentinel vent. During the
purge period the
TIMER
lamp Air Sentinel will be RED indicating the
purge is in process and no power is applied to the rest of the CLX-Ex.
At the complete of the purge, the
TIMER
lamp will go GREEN and
power will be applied to the rest of the system. As long as the proper
air supply conditions are met the CLX-Ex will continue to operate.
Do not apply power to the Air Sentinel controller unless the area
has been properly tested and is known not to contain explosive
materials.
5.2 Indicator Lamps
The indicator lamps are a very quick way to determine to operation of
the controller and thus the safety condition of the CLX-Ex.
Lamp Color Matrix
Function
Default
All lamps GREEN
Safe Operation
Power ON
TIMER
lamp RED
Instrument purging or Bypass
operation
Power OFF
PRESSURE
lamp RED
Unsafe Operation
Power OFF
BYPASS
lamp RED
Bypass Key Operating
Power ON
No Lamps on
No power applied to CLX-Ex
No power applied
everything off
Using the table above, you can quickly determine the operating
condition of the instrument. Under normal operation all GREEN lamps
should appear.
WARNING
!
