9 Block BASIC FUNCTION Device Functions Proline Promass 83 MODBUS RS485
110 Endress+Hauser
PRESSURE SHOCK
SUPPRESSION
MODBUS register:
Data type:
Access:
6404
5140
Float
read/write
The closure of a valve can cause brief but severe movements of the fluid in the
piping system, movements which the measuring system registers. The pulses
totaled in this way result in a totalizer reading error, particularly in the case of
batching processes. For this reason, the measuring device is equipped with
pressure shock suppression (= short-term signal suppression) which can eliminate
system-related “disruptions”.
! Note!
Note that pressure shock suppression cannot be used unless the low flow cut off is
active, (see function ON-VALUE LOW FLOW CUT OFF (6402) on Page 109).
Use this function to define the time span for active pressure shock suppression.
Activation of the pressure shock suppression
Pressure shock suppression is activated after the flow falls below the switch-on
point of the low flow cut off (see point a in graphic).
While pressure shock suppression is active, the following conditions apply:
• Current outputs → outputs the current corresponding to zero flow.
• Pulse-/Freq.-output → outputs the frequency corresponding to zero flow.
• Flow reading on display 0.
• Totalizer reading → the totalizers are pegged at the last correct value.
Deactivation of the pressure shock suppression
The pressure shock suppression is deactivated after the time interval, set in this
function, has passed (see point b in graphic).
! Note!
The actual flow value is displayed and output when the time interval for the
pressure shock suppression has passed and the flow exceeds the switch-off point
of the low flow cut off (see point c in graphic).
A0001285-en
Fig. 35 : Pressure shock suppression
m = Off-value (low flow cut off)
n = On-VALUE (low flow cut off)
a Active when value falls below the on-value of the low flow cut off
b Deactivated after specified time expires
c Flow values are again used to calculate the pulses
■ Suppressed values
QFlow
User input: max. 4-digit number, incl. unit: 0.00 to 100.0 s
Factory setting: 0.00 s
Function description
BASIC FUNCTION → PROCESS PARAMETER → CONFIGURATION
n
m
a
b
c
inactive
active
inactive
t
Pressure shock suppression
Command:
Valve closes
Q
Given time
After filling
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