IMR01H01-E4
16
7. FUNCTIONS
This chapter describes an outline of function of MA900/MA901.
7.1 PV Bias Function
The value set in the PV bias is added to the input value (actual
measured value) to correct the input value. The PV bias is used
to correct the individual variations in the sensors or when there
is difference between the measured values (PV) of other
instruments.
5.4 Setup Setting Mode (P. 8)
7.2 Digital Filter Function
This is a software filter which reduces input value variations
caused by noise. If the time constant of this filter is set
appropriately to match the characteristics of the controlled
object and the noise level, the effects of input noise can be
suppressed. However, if the time constant is too small, the filter
may not be effective, while if the time constant is too large, then
the input response may actually deteriorate.
5.4 Setup Setting Mode (P. 8)
7.3 Multi-Memory Area Function
This function is to store the parameters such as temperature set
value (SV), etc. in up to 8 memories. The parameters which can
be stored as one of memories are set value (SV), alarm 1, alarm
2, alarm 3, proportional band, integral time, derivative time, anti-
reset windup, cool-side proportional band, overlap/deadband,
setting change rate limiter and use/unused of channels. The
parameters stored in one of 8 memories retrieved at necessity
and used for control. The memory area used for this control is
called the control area.
5.3 SV Setting & CT Monitor Mode (P. 7),
5.5 Parameter Setting Mode (P. 10)
8
7
6
5
4
3
2
1
Memory area
Control area
Parameter
CH1 CH2
CH3
CH4
Set value (SV)
Control loop break alarm
Control loop break alarm deadband
Alarm
1
Alarm
2
Alarm
3
Proportional band
Integral time
Derivative time
Anti-reset windup
Cool-side proportional band *
Overlap/deadband *
Setting change rate limiter
Use/unused of channels
＊
These setting items can not be set in MA901.
7.4 Setting Change Rate Limiter Function
The setting change rate limiter functions so as to change the set
value (SV) gradually toward the set value after being changed.
This limiter sets how much the set value is changed upward or
downward per minute.
5.5 Parameter Setting Mode (P. 10)
Example:
7.5 Scan Display Function
The scan display function is for automatically selecting the
PV/SV monitor at the scan interval time for the measured values
(PV) and set values (SV) corresponding to all of the channels
within the control area. This function enables the control trend of
each channel to be checked.
•
The transfer speed of the scan display is set with the interval
time of setup setting mode (P. 9).
•
Use the CH key to stop or start of the scan display function.
The CH key operation is as follows.
Press the CH key for 2 sec
Scan start.
Press the CH key
Scan stop.
The channel number can be
changed like 1
→
2
→
3
→
4
→
1
･･･
during scan stopping.*
* In case of MA901:
1
→
2
→
3
→
4
→
5
→
6
→
7
→
8
→
1
･･･
•
During display scanning, each unused channel is skipped.
The unused channel means the channel set to
oFF
in
used/unused channels of the parameter setting mode.
•
When the channel number is manually changed, both PV and
SV corresponding to any unused channel are also scan-
displayed.
•
The scan display can be made even at any of RUN and STOP.
Scanning display examples:
When scanning PV/SV corresponding to channel 1 to channel 4
in the control area 1 at 2 seconds intervals:
When scanning PV/SV corresponding to channel 1 to channel 4
(channel 3: unused channel) in the control area 1 at 2 seconds
intervals:
PV
CH
SV
AREA
PV
CH
SV
AREA
PV
CH
SV
AREA
PV
CH
SV
AREA
PV
CH
SV
AREA
PV
CH
SV
AREA
<Increasing set value to higher value>
Increase
gradually
Change set value at
this point
SV
SV
[After change]
Time
SV
[Before change]
<Decreasing set value to lower value>
Decrease
gradually
Time
SV
SV
[Before change]
SV
[After change]
Change set value at
this point
PV
CH
SV
AREA
Press the CH
key for 2 sec.
2 sec
2 sec
2 sec
Press the CH
key for 2 sec.
2 sec
2 sec