Rosemount 3491, Справочное руководство, Страница: 98 / 152

Reference Manual
00809-0100-4841, Rev. AA
May 2007
Rosemount 3490 Series
4-66
The maximum rate at which the unit can output a totaliser pulse is entirely
dependent on the pulse width. Parameter P534 also determines the width of a
pulse that is output by a Sampler relay. (See “Sampler Relay“ on page 4-52).
Menu:
MAIN MENU / MONITOR / [CONTROL UNIT /] READINGS / TOTALISER
D828 Totaliser 1
This displays the Totaliser 1 count, which is the cumulative totalised flow. To
add this to the primary display, see “Primary Display Options“ on page 4-72.
Totaliser 2 (Daily totalised flow) on Model 3493
This is an 8-digit totaliser showing daily total flow (midnight to midnight)
through a flow structure. It is automatically re-set to zero at each midnight.
A Totaliser relay can be configured to output a pulse for each increment (by
one) to the Totaliser Count parameter. For information on setting up a relay to
output 'totaliser' pulses, see Section “Relays“ on page 4-40.
NOTE:
For totalising examples, see “Totalising examples“ on page 4-68.
NOTE:
Totalisers are set-up to operate with an input of PV in units/second. If the PV
value is a volumetric flow rate (e.g. m
3
/hour), the totaliser can accumulate this
volume of flow, therefore, giving the total volume throughput.
Menu: MAIN MENU / SETUP / [CONTROL UNIT /] OUTPUT / TOTALISER
P532 Total 2 Factor (Factor default is 0.0)
One count is added to the Totaliser 2 Count (D829) for a quantity of liquid as
defined by this parameter. The display unit of measurement for D829 is
defined by parameter P533.
P533 Total 2 Units (Factory default is "None")
This parameter defines the units for the Totaliser 2 Count (D829).
P534 Pulse Width (Factory default is "100ms")
A Totaliser relay is energised for a programmed duration (P534) each time the
Totaliser Count (D828 or D829) is incremented. Parameter P534 controls the
'On' time and 'Off' time - i.e. pulse width - and may be a value of between
10ms and 2500ms (0.01 to 2.5 seconds), changeable in steps of 10ms.
The maximum rate at which the unit can output a totaliser pulse is entirely
dependent on the pulse width. Parameter P534 also determines the width of a
pulse that is output by a Sampler relay - see “Sampler Relay Output“ on
page 4-67.
P536 Total 2 Source (Factory default is "MCU PV")
Use this parameter to select whether the MCU PV (D800), MCU SV (D801),
MCU TV (D802) or MCU FV (D803) value is to be totalised over a 24 hours
period for the Totaliser 2 Count (D829). Alternatively, select "None" if not
requiring Totaliser 2.