TOHO ELECTRONICS TTM200 User Manual
Page 167
48-7009-E
6-19
■ AT start screen
SEt04
CNt
Setting content
Initial value
16
At
Use the / key for start and stop.
PV/SV is displayed during AT.
oFF
The screen is used for starting AT.
Pressing the key or key allows start/stop of AT.
After setting the AT start/stop in the key function setting, pressing the FUNC key allows the AT start/stop. See page 6-11.
After setting the AT start/stop in the DI function setting, DI allows the AT start/stop. See pages 6-57 and 58.
Note The AT start/stop is not allowed on the AT start screen when the AT start/stop is set for DI or the FUNC key.
■ Proportional band setting
SEt04
CNt
Setting content
Initial value
17
P1
0.1 to 200.0 (%)
3.0
Set the proportional band.
The proportional band for the heating cooling control is the one on the heating side.
The proportional band for the heating control is located as shown in the diagram below.
The proportional band for the cooling control is located in the upper side of SV in the diagram.
Temperature
Time
Proportional
band range
SV
The proportional band range can be calculated, using the equation below.
Proportional band range = (SLH - SLL) × P 1
SLH: SV limiter upper limit
SLL: SV limiter lower limit
Example: When SLH = 1200°C, SLL = 0°C, and P 1 = 3.0 %;
(1200°C - 0°C) × 3 % = 36°C.
Thus, the output gradually decreases from the one at the temperature 36°C below SV.
In general, wider proportional range results in a slower initial rise.
A narrower proportional range may result in that the control goes too far (overshoot), or forms waves (hunting) to cause
unstable output, although the initial rise is faster.