46
£
Option 8.1 - Setpoint 2 zero value (0 - 999 / 00.0 - 99.9 / 0.00 - 9.99)*
When setpoint 2 is selected, this is the measured value which is displayed when the minimum signal
level (0V or 4mA) appears at the modulation input. This parameter is not used when a track modula-
tion input type is selected.
Option 8.2 - Setpoint 2 span value (0 - 999 / 00.0 - 99.9 / 0.00 - 9.99)*
When setpoint 2 is selected, this is the measured value which is displayed when the maximum signal
level (5V or 20mA) appears at the pressure input. This parameter is not used when a track modula-
tion input type is selected.
Option 8.3 - Setpoint 2 control value (0 - 999 / 00.0 - 99.9 / 0.00 - 9.99)
This is the control value which is used in the PID control loop for setpoint 2. When the unit is in auto
mode, the PID control loop will modulate the boiler to maintain the measured value at the same level
as this parameter.
Option 8.4 - Setpoint 2 proportional term (0 - 999 / 00.0 - 99.9 / 0.00 - 9.99)
This is the width of the proportional band that is used by the PID control loop for setpoint 2. If the
setpoint was 5.00 bar, and this term was set to 1.00, then the proportional band would be from 4.00 to
5.00 bar. A value of 0 means no proportional band.
Option 8.5 - Setpoint 2 integral term (0 - 100)
This is the integral term which is used in the PID control loop for setpoint 2. It may be set to any
value from 0 to 100, where 0 means no integral term.
Option 8.6 - Setpoint 2 derivative term (0 - 100)
This is the derivative term which is used in the PID control loop for setpoint 2. It may be set to any
value from 0 to 100, where 0 means no derivative term.
Option 9.0 - Setpoint 2 control limit type (0 - 2)*
This option parameter defines the control limit type for setpoint 2, where:
Option 9.1 - Setpoint 2 low limit control value (0 - 999 / 00.0 - 99.9 / 0.00 - 9.99)
If the boiler is off due to a controlled shutdown, this parameter defines the measured value at which
the boiler will be turned on again.
Option 9.2 - Setpoint 2 high limit control value (0 - 999 / 00.0 - 99.9 / 0.00 - 9.99)
If the boiler is on and firing, this parameter defines the measured value at which the boiler will be
turned off via a controlled shutdown.
Option 9.5 - Setpoint 2 warming limit (0 - 999 / 00.0 - 99.9 / 0.00 - 9.99)
If the boiler’s measured value is below the value of this parameter and the unit is in auto or sequenc-
ing mode, the burner will be held at low fire.
Note: the warming limit is only applied to the first start-up after the “Burner On” signal (Terminal
PB7) has been detected. Re-starts after a Controlled Shutdown will not use the warming limit if PB7
is maintained on.
0
No limits.
1
Absolute limit.The values entered in option parameters 9.1 and 9.2 are the actual limit values.
2
Deviation limit. The values entered in option parameters 9.1 and 9.2 represent a deviation from the setpoint 1 control value.
This means that if the setpoint control value is changed, the limits are automatically changed correspondingly.
