Toshiba L5232 manual Rate-of-Change Limit Value and Control Time, Rate-of-change limit value, 110

6F8A0917

8.2.20 Rate-of-Change Limit Value and Control Time

The rate-of-change limit is the function to prevent a sudden change in flow indication of the converter when the measurement flow signal contains excessive noise.

Damping constant is also effective to prevent indication variations by increasing its value but the rate of change limit control is effective against a sudden change in flow indication that the damping constant cannot eliminate.

The following parameters can be set here:

(1)Rate-of-change limit value

(2)Rate-of-change control time

Note: To use the rate-of-change limit function, it is necessary to set both (1) and (2). If either one is set to zero (factory setting value), this function does not work

When not using the rate-of-change limit function, set zero to either one of these items.

Rate-of-change limit value

Indication change is controlled within the limit value* against variations of measurement flow signals.

*Indication variation per approx. 40ms will be controlled to within the limit value (in percent of span).

The rate-of-change limit value can be set within the range of 0 to 30% in increments of 0.1%. In the case of multi-range setting, the value is indicated in percent of the range in operation. If 0 is set, the rate-of-change limit function does not work.

Rate-of-change control time

If the time used to control the indication against variations of measurement flow signal exceeds the control time, the rate-of-change control will be turned off. (Flow indication will be output directly without the rate-of-change limit function.)

Control time can be set within the range of 0 to 20s in increments of 1s. If 0 is set, the rate-of-change limit function does not work.

Checking the rate-of-change limit setting

Proceed as follows to check the rate-of-change limit setting.

How to check the limit value is shown below.

To check the control time, select the function “M2: LIMIT TIME.”

Switch operation	Display example		Description
	M1: LIMIT RATE		Select M1: LIMIT RATE from the setting item selection menu.
	05.0	%	The currently set rate-of-change limit value appears.

M1: LIMIT RATE

Returns to the menu of setting item selection.

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