This paper investigated that how the personal computer system showed the control characteristics, some deviations from the targetting time series of discarge and automatic control of the gate.
At the first stage of this experiment, the computer was connected with electromagnetic flow meter and a frequency converter of a motor pump. Here the maximum discharge was 30l/s.
In this condition, the deviation in the small discharge of sine curve was estimated by added hydraulic experiments, under the some valve opening condi tions.
Concretely, targetting sine curve was given with 3～6l/s in mean, 0.5～1.0l/s in amplitude and 0.5～1.0 min in period. And valve opening ratio was 5,15 and 40%. Then 15% showed the best(in minimum) deviation, and this was estimad as the limit of this 8 bits personal computer system.
Second, the measurement system of the water height in the open canal and gate control system connected with the water height by a sensor, main and sub control units and personal computer was built up.
Thanks to this system, the data processing facilities made great progress, especially in setting the time constant parameters which were very ease to gain in the BASIC PROGRAM.