LRF-3000S Ultrasonic Transit-time Flow meter
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5.8.
Totalizer Pulse Output
Each time the flow meter reaches a unit flow, it may generate a totalizer pulse output to a remote counter.
The totalizer pulse output can be transmitted through OCT or a relay. Therefore, it is necessary to configure OCT
and the relay accordingly. (Please refer to Window M33 and M34). For example, if it is necessary to transmit the
positive totalizer pulse through a relay, and each pulse represents a flow of 10m3, the configuration is as follows:
In Window M41-Unit, select the totalizer flow unit "m3";
In Window M41-MULT, select the scale factor "e. x10";
In Window M34-Option, select "g. POS Total ";
5.9.
Alarm Programming
The on-off output alarm is generated through OCT or transmission to an external circuit by opening or closing a
relay. The on-off output signal is activated under the following conditions:
(1)
Signal not detected;
(2)
Poor signal detected;
(3)
The flow meter is not ready for normal measurement;
(4)
The flow is in the reverse direction (back flow).
(5)
The analog outputs exceed span by 120%.
(6)
The frequency output exceeds span by 120%.
(7)
The flow rate exceeds the ranges configured (Configure the flow ranges using the software alarm system.
There are two software alarms: Alarm#1 and Alarm #2.
Example 1: When flow rate exceeds 300 ~ 1000 m
3
/h, in order to program the relay output alarm, Complete the
steps as follows:
(1)
In Menu 35, Alarm1 LowL 300;
(2)
In Menu 35, Alarm1 Upper 1000;
(3)
In Menu 34, Relay Setting-Option-d.Alarm1
5.10.
4-20mA Analog Output Calibration
Attention
Each flow meter has been calibrated strictly before leaving factory. It is unnecessary to carry out
this step except when the current value (detected while calibrating the current loop) displayed in
Window M32 is not identical with the actual output current value.
The hardware detect window must be activated prior to calibration the Analog Output. The procedure is as
follows:
Menu 62 is for 4-20mA calibration, if you need enter the pass word to enter. With no effect to next power on, this
window will close automatically as soon as the power is turned off.
Use “
” and “
” to switch. Calibrate the current loop 4mA output. Use an ammeter to measure the output
Attention
Make sure to select an appropriate totalizer pulse. If the totalizer pulse is too big, the output
cycle will be too long; if the totalizer is too small, the relay will operate too faster, you may
shorten the life of the relay, as well as skip some pulses. The totalizer is recommended to
transmit within the range of 1 ~ 3 pulse per second.
