instrument is in the stoP status, the program will start-up and run from the StEP NO. set.
The stoP function can be programmed into the program StEP. The running StEP NO. Can be set at the
same time. The stoP operation can also be performed manually at any time. (After stoP operation is done,
the StEP NO. Will be set to 1, but user can modify it again).
Power cut /resume event handling: There are four event handling method selectable for power resume
after power cut.
PV startup and PV preparation function: At the beginning of starting a program, resuming a program
after power cut or continuing to run a program after it is just modified, the PV (process value) are often quite
different from the setpoint. PV startup function and PV preparation function can make PV and setpoint
consistent, and avoid unexpected result.
When PV startup function is enable, the instrument will adjust the running time automatically to make the
expected setpoint is the same as the current PV.
For example, the program is set that the temperature will be raised form 25℃ to 625℃ in 600 minutes.
But the current PV is 100℃, then the instrument will automatically adjust the running time to 75 minutes,
and then run the program.
Preparation function(rdy): when start program control, when all setting is correct, then the preparation
work will be avoided, otherwise, the function will be started to correct unnormal parameters. You can set in
run parameter so as to make sure of high accuracy.
Curve fitting: curve fitting is adopted as a kind of control technology for AI-518P series instrument. As
controlled process often has lag time in system response, by the way of curve fitting the instrument will
smooth the turning point of the linear heating-up, cooling-down and constant temperature curves
automatically. The degree of the smooth is relevant with the system’s lag time, the longer of the lag time, the
deeper of the smooth degree. On the opposite the smooth function will be weaker. Generally the shorter of
the process lag time (such as temperature inertia), the better of the program control on effect. By the way of
the curve fitting to deal with the program curves, will avoid overshoot. Note: The characteristic of the curve
fitting will force the program control to generate fixed negative deviation during the linear heating-up and
fixed positive deviation during the linear cooling-down, the deviation is direct proportional to the lag time (t)
and the speed of heating-up (cooling-down). This phenomenon is normal.
7.2 Programming and operation editting
Programming of AI series instrument has uniform format of temperature-time-temperature, which means
that temperature set for current StEP will change to temperature set for next StEP after the time set for the
current StEP. The unit of temperature set is ℃ and the unit of time set is minute. The following example
includes 6 steps, which is linear temperature heating up, constant temperature, linear temperature cooling
down, jump cycling, ready, Hold and event output.
StEP1: C01=100 , t01=30 Start linear temperature heating up from 100℃, and the time needed is 30
minutes.
StEP2: C02=400 , t02=60 Raise temperature to 400℃, slope of raising curve is 10℃/minute, and the time
for temperature to remain constant is 60 minutes.
StEP3: C03=400 , t03=120 The StEP for temperature cooling down, slope of cooling curve is 2℃
/minute, and the time needed is 120 minutes.
StEP4: C04=160 , t04=-35 Temperature cool down to 160℃, then alarm 1 is triggered, and the program