Liquid Controls SP3850 - Manual (Page 20)

SP3850 Flow Computer
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5.2 General Operation
The unit can display: Rate, Total, Grand Total, Temperature, Pressure, Density,
Presets and Time of Day. In addition, input frequencies, computed K-factors
and viscosities can be observed. The Temperature and Pressure or Density can
be displayed even if you are using the Volumetric Flow Equation (a Temperature
or Density sensor must be installed). The unit can perform Mass or Corrected
Volume equations using a temperature, pressure or density sensor (these
equations can be computed without Temp/Dens/Press sensors by using user
defined default values). The unit can be programmed to perform Ratemeter/
Totalizer or Batching functions (see section 6.4.2, INSTRUMENT TYPE
Submenu).
5.3 Ratemeter/Totalizer Operation
The Ratemeter/Totalizer mode is used primarily to monitor flowrate and
accumulated total. The relays can be used to trigger flow, total, temperature
pressure or density alarms.
5.3.1 Password Protection for Rate/Total mode
After an Operator and/or Supervisor Password is entered in the setup mode
(see section 6.4.23, ADMINISTRATIVE SETUP submenu), the unit will be
locked. The unit will prompt the user for the password when trying to perform
the following functions:
Clear Total
Clear Grand Total
Enter Menu
Edit Preset 1 (PRE 1 Key)
Edit Preset 2 (PRE 2 Key)
The Supervisor password should be reserved for supervisors. The Supervisor
password will allow access to restricted areas of the Setup and Test menus.
5.3.2 Relay Operation in Rate/Total mode
Up to four relays are available (two standard) for alarm outputs. The relays can
be assigned to trip according to rate, total, temperature, pressure, density
readings or general system alarms. The relays can be programmed for low or
high alarms.
Preset 1 (RLY1) and Preset 2 (RLY2) are easily accessible by pressing the
PRE 1 or PRE 2 key on the front panel. Preset 3 and Preset 4 are accessible
only through the setup menu.
5.3.3 Pulse Output in Rate/Total mode
The isolated pulse output (open collector) is menu assignable to Volume Total
and either the Corrected Volume Total or Mass Total. The pulse output
duration can be set for 10mS (50 Hz max) or 100mS (5 Hz max). A pulse output
scale factor (pulse value) can be set to scale the pulse output. The pulse output
is ideal for connecting to remote totalizers or other devices such as a PLC. See
section 1.3 for electrical specifications.
5.3.4 Analog Output in Rate/Total mode
The analog output is menu assignable to correspond to the Volume Rate,
Corrected Volume Rate or Mass Rate, Temperature, Pressure, Density,
Volume Total or Corrected Volume Total or Mass Total. The analog output is
ideal for "trend" tracking using strip chart recorders or other devices.
General
Operation
Rate/Total
Operation
Password Protection
(Rate/Total mode)
Relay Operation
(Rate/Total mode)
Pulse Output
(Rate/Total mode)
Analog Output
(Rate/Total mode)