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INPUT TYPE
PROBLEM
PROBLEM
DESCRIPTION
0-5 V
0-10 V
Broken or short-circuited
wiring
The error will
not
be recognized by the
Input Error
function. In its display,
the equipment will show the lower value of the configured range.
0-50 mV
Broken wires
The error will be recognized by the
Input Error
function. In its display, the
device will show the
message.
Short Circuit
The error will
not
be recognized by the
Input Error
function. In its display,
the equipment will show the lower value of the configured range.
Table 4
–
Input error types
4.2.4
ALARM TIMER
The alarm can be triggered in the following ways:
•
Defined time alarm trigger
•
Delayed alarm trigger
•
Intermittent alarm trigger
The table below shows the behavior of the alarm outputs with the trigger variations defined by the time ranges
T1
and
T2
, available in
parameters
t1A1
,
At2a1
,
t1A2
,
t2A2
,
t1A3
,
t2A3
,
t1A4
and
t2A4
(
CFG
>>
ALM
>>
t1A1
or the desired timer parameter T1 or T2
).
Table 5
–
Alarm timer functions
The alarm indicators light whenever an alarm condition occurs, regardless of the alarm output status (see
section).
4.2.5
CONTROL MODES
N20K48 Modular Controller
has 2 control modes: Automatic mode or Manual mode, as configured in the
Ctr
parameter of the Operation
Cycle (see
section).
•
In Automatic mode (
Ctr
>>
auto
), the controller sets the MV value to be applied to the process. It is based on the parameters set (SP,
PID, etc.).
•
In Manual mode (
Ctr
>>
MAN
), you need to set this value.
4.2.6
PID CONTROL MODE AND ON/OFF CONTROL MODE
The Automatic control mode (
Ctr
>>
auto
) has 2 control strategies: PID control and ON/OFF control.
•
In PID control mode, the PID control action is based on a control algorithm that acts on the deviation of the PV value from the SP
value and based on the set
Pb
,
Ir
and
Dt
parameters. To configure this control mode, you must set the
Pb
parameter to a value
other than
0
.
•
In ON/OFF control mode, the controller must act with 0 % or 100 % power when the PV deviates from the SP value. To configure
this control mode, you must set the
Pb
parameter to a value other than
0
(Once this is done, the parameters
Ir
and
Dt
will not be
displayed).
For more information about the parameters
Pb
,
Ir
and
Dt
section.
4.2.7
INITIAL ALARM BLOCK FUNCTION
The
Initial Alarm Block
function (
CFG
>>
ALM
>>
bL.A1
,
bL.A2
,
bL.A3
or
bL.A4
) prevents the alarm from being triggered during an
alarm condition when the controller is on or after the operation transition (
RUN
>>
no
→
YES
). The alarm will be enabled after the process
goes through a non-alarm condition.
The initial block is useful when one of the alarms is set as a minimum value alarm (
CFG
>>
ALM
>>
Fu.A1
or the desired alarm number >>
Lo
), for example. This may cause the alarm to be triggered during process startup (a behavior that is often undesired).
The initial block is not valid for the Open Sensor Alarm function (For more information about this and other types of alarms, see table in
section).
4.2.8
SQUARE ROOT EXTRACTION FUNCTION
Once this function is enabled (
CFG
>>
IN
>>
SQRT
), the controller will display the value corresponding to the square root of the applied input
signal.
Available only for the following
analog linear signal
input: 0-20 mA, 4-20 mA, 0-50 mV, 0-5 V and 0-10 V (see
section).
