IRIS S55XX SERIES VIEWING HEADS APPLICATION MANUAL
PAGE 10
the P520 / P522 control panel. (See “RETURN TO
DEFAULT SETTINGS” on Page 13.)
STORED VIEWING HEAD SETTINGS
Viewing Head settings are stored in an EEPROM in
the particular signal processor to which it is attached.
In the event of a power down or power loss, these
settings will be restored upon power up. If an S550B
viewing head is replaced with another, the stored set-
tings will be applied to the replacement. This simpli-
fies field replacements since these viewing heads are
made to close tolerances, and will work virtually the
same as the viewing head it replaced.
ASSIGNING SETTINGS TO CHANNELS A AND B
The P520 and P522 signal processors, when used with
an S550B viewing head, allows assigning one group
of settings to Channel A and another group to Chan-
nel B.
If the CHAN SEL input to the P520 or P522 is open or
de-energized, then the Channel A lighted push-button
on the front panel will be ON. If a voltage of 7.5V to
30V is applied across the two CHAN SEL inputs, then
Channel B will be selected and the Channel B lighted
push button will be ON.
When Channel A is selected, any P520 or P522
parameters changed (this includes Flame ON and
Flame OFF set points and the analog gain of the
P520/P522 as well as the gain and filter selection
for the S550B) will be stored for use when Channel
A is selected. Similarly, when Channel B is selected
any P520 or P522 changes are stored for use when
Channel B is selected. When the CHAN SEL input is
changed, the P520/P522 changes the set points in use
accordingly and sends the appropriate gain and filter
selections to the S550B viewing head.
In the P520 and P522, it is possible to observe and
change settings for the channel which is not selected,
by pressing the other channel push button - it will blink
indicating that the selection is temporary - and then
proceed as if the CHAN SEL input had changed.
This method is available for examining or chang-
ing Flame ON and Flame OFF set points and other
settings in the P520 and P522. The same proce-
dure applies to manually changing viewing head
settings when the desired channel is not selected:
press the push-button for the desired channel and
then proceed.
During the process of examining or changing the
S550B settings, with the Channel A and B (NO and
YES) push buttons, the red LED for the channel
which the changes apply to, will be blinking.
A visual check should be made to see which channel
push-button is lighted when the S550B settings are
being reviewed or changed. It is possible to unin-
tentionally get into the S550B CAL modes with the
wrong channel selected.
USING TWO VIEWING HEADS ON THE P520/P522
The P520 and P522 signal processors are capable of
supporting two viewing heads by using the V.H. A
and V.H. B inputs. To achieve this, a 24VDC channel
select signal must be applied simultaneously to the
coil of the VH select relay and to the channel select
input. When the channel selection is changed, the
alternate set of data inputs from viewing head B will
be switched into the signal processor by the VH select
relay and the processor will apply a different group of
set points and gains in response to the A/B Channel
switch.
There are no restrictions on how viewing heads may
be mixed between the two channels. An S550B can
be used on one channel and an S511 on another, or an
S552B on one channel and an S556B on another. It
should be noted however, that only one viewing head
can be active at any given time.
The earlier 500 series viewing heads - Models S506,
S511 and S512 - are not adjustable remotely as the
S550B family of viewing heads are. The P520 or P522
signal processors will continue to work as they have
in the past with an earlier S5XX series viewing head
when the channel with that viewing head is selected.
BEFORE MAKING ADJUSTMENTS
Before making any adjustments to the S550B, the
flame signal strength should be optimized by aim-
ing the viewing head at the most intense part of the
flame as explained in the two previous sections “IR
DETECTOR” and “UV DETECTOR”. This operation
should be done with the default setting
CALIBRATING THE S550B
The calibrate feature is designed to aid with the setup
of the viewing head. It is basically an automatic gain