E+E Elektronik EE771 Series - 5.1.6. Pulse Output Mode

27
Window
t
Nm
3
/h
0
1
0
1
set point 1
set point 2
NC (activate to open)
NO (activate to close)
  
The relay is activated as long as the measuring value is
between the values of set point 1 and set point 2.
The hysteresis of each set point is fixed at 0.2% of the meas-
uring range.
e.g.: set point 1 = 100 Nm
3
/h; set point 2 = 80 Nm
3
/h;
hysteresis of each set point is 1 Nm
3
/h (0.2% of 500 Nm
3
/h)




80 Nm
3
/h = set point 2
100 Nm
3
/h = set point 1
99 Nm
3
/h = set point 1 - hysteresis
79 Nm
3
/h = set point 2 - hysteresis
5.1.6. Output mode – pulse
If output 2 is configured for pulse, the measurand can be consumption only. Under “Pulse”, the duration of the
pulse and the pulse value (Significance level of pulse) can be freely configured.
Volume Flow [m
3
/h] Number of Pulses
HourPulse Value [m
3
/Pulse]
=
The duration of the pulse can be set between 0.02 and 2 seconds.
e.g. Duration of pulse = 100ms; one pulse for each Nm
3
consumed
The pulse – interval – ratio must be at least 1 : 2, meaning that the duration of the pulse interval must be at
least twice the duration of the pulse itself.
t
OUT 2
1/3 min. 2/3
≥ 2 s
Calculation of the minimum “pulse value” or the maximum “pulse duration”.
IMPW_MIN = NORMV_MAX [m
3
/h] * IMPL [s] / 1200
IMPL_MAX = IMPW [m
3
] * 1200 / NORMV_MAX [m
3
/h]
IMPW pulse value [m
3
]
IMPL pulse length (duration) [s]
IMPW_MIN minimum pulse value [m
3
]
IMPL_MAX maximum pulse length (duration)
NORMV_MAX expected maximum volume flow (Nm
3
/h)
5.2. Minimum flow shutdown
The minimum flow shutdown is switched on and off using the “active” checkbox.
Iftheoutputsignalis≤thantheset“Shutdownvalue”,theflowmeterissues0ontheanalogueoutput.