59
®
If both inputs are selected to have the same function, input 2 is ignored and input 1 is used.
The auxiliary input functions are detailed below.
0
- No function. The input is ignored.
1
- Setpoint select. The level of the input determines whether setpoint 1 or setpoint 2
is used. A low level selects setpoint 1.
2
- Release to ignite. Once the system has purged, the drives will move to their ignition
positions. A high level on the input will turn the ignition triac on and fire the burner.
3
- Release to modulate. Once the burner has ignited and the ignition time has elapsed,
the drives will move to their low fire positions. After the low fire hold time has elapsed,
a high level on the input will permit the drives to modulate.
4
- Lead boiler select. If multiple boiler sequencing has been commissioned, a high level
on the input selects the unit as the lead boiler.
5
- Fault mute. The input performs the same function as the fault mute key. If there is a
high level on the input for approximately one second, the alarm is muted, a high level on
the input for approximately three seconds, all cleared faults are removed
6
- Trim on/off. The input is used to enable or disable the oxygen trim function. Option
parameter 30.5 (oxygen input function) must be set to 1.
Options 16.1, 16.2 and 16.3 - Digital output functions (0 – 12)*
Digital outputs 1, 2 and 3 (terminals PB8, PB9 and PB10 respectively) may be configured to perform
a variety of different functions.
Option parameter 16.1 determines the function of digital output 1, parameter 16.2 determines the
function of output 2, and parameter 16.3 determines the function of output 3.
The digital output functions are detailed below.
0
- No function. The output will always be off.
1
- Manual selected from keyboard. The output will be turned on when hand modulation
mode has been selected from the keyboard.
2
- O
2
alarm. The output will be turned on when the measured oxygen level falls outside
the high or low alarm levels.
3
- Flue gas high alarm. The output will be turned on when a measured flue gas level
which is not oxygen exceeds its high alarm value.
4
- O
2
or flue gas alarm. The output is turned on when any measured flue gas level falls
outside the high or low alarm levels.
5
- Setpoint low alarm exceeded. The output is turned on when the setpoint low alarm
(determined by options 12.3 or 14.3) is activated.
6
- Setpoint high alarm exceeded. The output is turned on when the setpoint high alarm
(determined by options 12.4 or 14.4) is activated.
7
- Setpoint high or low alarm exceeded. The output is turned on when the setpoint low
alarm (determined by options 12.3 or 14.3) or the setpoint high alarm (determined by
options 12.4 or 14.4) is activated.
8
- Purging. The output is turned on when the drives are at their pre-purge positions and
the purge prove output is activated.
9
- Igniting. The output is turned on when the drives are at their ignition positions and
the ignition prove output is activated.
10
- Modulating. The output is turned on when the burner is modulating (for any
modulation mode, including sequencing).
11
- Auxiliary input 1 high alarm – The output is activated when auxiliary input 1
exceeds its high alarm value (see option parameters 53.X).
12
- Auxiliary input 2 high alarm - The output is activated when auxiliary input 2
exceeds its high alarm value (see option parameters 54.X).
