TOHO ELECTRONICS TTM-339 - Manual (Page 9)

- 9 -
4.4 Wait function
For the current step transferring to the next step, the next step does not begin if PV has not reached the wait zone
(similarly, if PV has overreached) after the step time elapsed.
However, if the wait time elapses, the next step begins at that point.
The above operation is executed by selecting 0 to 4 for each step, or by setting value for 1 to 4.
Selecting 0 indicates no function.
In the case of [the wait zone setting = 0], in-a- wait is effective until PV goes beyond SV.
Wait zone
Wait zone
Present step Next step
SV PV
In a wait
As PV enters into the wait zone, a transfer to
the next step is made.
Even if PV does not enter into the wait
zone, a transfer to the next step is
made when the wait time elapses.
4.5 Three-zone PID function
Numerical values of P, I, D and PC are switched over at each of the low, intermediate and high temperatures.
The ranges of the three zones are as follows:
- Low temperature (PID No. 1): SLL to intermediate point 1
- Intermediate temperature (PID No. 2): Intermediate point 1 to intermediate point 2
- High temperature (PID No. 3): Intermediate point 2 to SLH
4.6 Auto tuning function
Auto tuning starts at each of low, intermediate and high temperatures.
Auto tuning starts when the temperature at which the auto tuning is to be performed is set on each startup screen and the
RUN/STOP key is pressed or by an Auto tuning start command of the communication.
During the auto tuning, AT-1 (to 3) and SV are alternately displayed in the SV display digit ,and ATALL and PV are
alternately displayed in the PV display digit.
Re-pressing the RUN/STOP key results in a stop of the auto tuning.
If the auto tuning has not terminated 3 hours after its start, an AT error is established and the run stops, displaying
“ERR2.”
Attempting an auto tuning during an automatic run results in first a temporary stop and then start of the auto tuning.
During a manual run, the auto tuning is not possible.
4.7 PV start/SV start
At a start of the program run after selecting the PV start and SV start, the start SV indicates the following:
PV start:
The run starts from the ramp step of upward slope in which the measurement temperature is included.
In addition, the run starts from the elapsed time, of which amount is assumed to elapse to come to the start point.
The calculation is made with the start point of 0

C /0 digit.
For below 0

C /0 digit, the calculation is made with the elapsed time of 0 minute.
SV start: The program run starts from the SV start temperature setting.