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Date: 8-4-2010
Revision: 0
Form: 2396
algorithm. (Any Solas set to Use First will
precede any that are set to Equalize Run time.)
If set to Use Last, then this burner will be used
only after all Use First and Equalize Runtime
Solas have been brought online.
SLAVE SEQUENCE ORDER: 0-255
Slave sequence order is used to determine the
order in which Solas will be used (staged on) for
those Solas which the same Slave mode setting.
Numbers may be skipped, that is 3 will be first if
there is no 1 or 2. Note: For Equalize Runtime
purposes, 1 does not mean the Sola will be used
first every time; that will vary over time based on
the master's run time equalization scheme. In
this case the sequence number determines the
relative order in which Sola controls will be used
in a round-robin scheme. If the slave sequence
number value is zero, then the slave Sola's
ModBus address will be used instead. If two
Solas which are set the same mode both have
the same sequence number then an alert will
occur and the order in which they are used will
be arbitrary and is not guaranteed to be
repeatable.
DEMAND-TO-FIRING DELAY: MM:SS OR
NONE
This delay time is needed by the LL master to
determine the length of time to wait between
requesting a slave Sola to fire and detecting that
it has failed to start. It should be set to the total
time normally needed for the burner to transition
from Standby to Run, including such things as
transition to purge rate, prepurge time, transition
to lightoff rate, all ignition timings, and some
extra margin.
BASE LOAD RATE: RPM OR %
This specifies the preferred firing rate of a
burner, which is used for some types of control
algorithms.
FAN DURING OFF-CYCLE RATE: RPM OR %
(0=DISABLE)
This determines if or where the fan is to be
operating during the standby period.
4.7 LL MASTER OPERATION AND
SETUP
LL master operation is subdivided into the
following functions:
• Overall control - The LL master has
parameters that enable and disable its
operation.
• Periodic data polling - The LL master uses
polling to discover new slave Sola devices and
to periodically refresh the information it has
about a known slave Sola devices.
• Slave control - the LL master sends each
active slave a command and also performs a
slave status read for each known slave device. It
also sends a Master status broadcast that is
heard by all slaves.
• Slave status manager - The LL master keeps
track of slave status for each Sola that is
enabled as a slave device.
• Demand and priority - different sources of
demand can cause the LL master to operate in
different ways. These sources have a priority
relationship.
• Modulation - each demand source has one or
more setpoints that may be active and an
operation sensor. These are used to detect turn-
on and turn-off conditions. The difference
between operating point and setpoint
determines the LL master's firing rate.
• Stager - the stager determines when slave
Solas should turn on as the need for heat
increases, and when they should turn off as the
need for heat decreases.
Rate allocation - the PID block's output is used
to determine the firing rate of each slave Sola
using various rate allocation techniques.
• Add-stage methods - various methods can be
used to determine when a new stage should be
added.
• Drop-stage methods - various methods can
be used to determine when a stage should be
dropped
• Sequencer - the Sola sequencer determines
which Sola will be the next one to turn on or turn
off.
4.7.1 OVERALL CONTROL
LL MASTER ENABLE: DISABLE, ENABLE, LL
MASTER MODBUS PORT: MB1, MB2 If
Disable is selected then all LL master functions
are inactive. If Enable is selected then it acts as
the active bus master on the ModBus port it is
assigned. LL OPERATION SWITCH: OFF, ON
This controls the LL master in the same way that
the Burner switch controls a stand-alone Sola. If
"On" then the LL master is enabled to operate. If
this parameter is "Off" then the LL master turns
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