ATI
Q45C2 2E Conductivity System
Part 4 – Configuration
O & M Manual
Revision K (01/07)
- 42 -
Fail
Out
This function enables the user to define a specified value
that the main current output will go to under fault conditions.
When the Relay Option Board is installed, the display will
read
Fail Out #1
. When enabled to
ON
, the output may be
forced to the current value set in
Fail Val
(next item.) With
the Fail Out setting of ON, and a Fail Val setting of 6.5 mA,
any alarm condition will cause the current loop output to drop
outside the normal operating range to exactly 6.5 mA,
indicating a system failure that requires attention.
Press ENTER to initiate user entry mode, and the entire
value will flash. Use the UP arrow key to modify desired
value; selections are
ON
,
OFF
. Press ENTER to store the
new value.
AC POWERED UNITS ONLY
*Failsafe
This function allows the user to set the optional system
relays to a failsafe condition. In a failsafe condition, the relay
logic is reversed so that the relay is electrically energized in
a normal operating state. By doing this, the relay will not
only change state when, for example, a conductivity limit is
exceeded, but also when power is lost to the controller.
When failsafe is selected to be ON, the normally-open
contacts of the relay will be closed during normal operation.
In an attempt to make this configuration less confusing, the
LCD icon logic is reversed with this setting, and the icon is
OFF under this normal condition. Therefore, when the trip
condition occurs, the closed N.O. contacts will be opened
(relay de-energized), and the LCD icon will illuminate. In
addition, a power fail would also cause the same contacts to
open.
AC OPERATED UNITS ONLY
*Rly A Mode
Relay A can be used in three different ways: as a setpoint
control, as a fail alarm, or as a HI-LO alarm band. The three
settings for Rly A Mode are
CON
,
FAIL
and
AL
.
The
CON
setting enables normal control operation for Relay
A, with settings for setpoint, hysteresis, delay and phasing
appearing in the CONFIG menu automatically. See Figure
4-3 for further details.
The
FAIL
setting enables the fail alarm mode for Relay A.
Relay A will then trip on any condition that causes the FAIL
