Hoffer Flow Controls HIT-2A, User Manual

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Operation and Maintenance 23
HP-306
6. OPERATION AND MAINTENANCE
6-1 Operation
A suitable pulse producing device or flow meter is wired to the HIT-2A
Signal Input terminals 1 (Sig +) and 2 (Sig -). The Signal Input circuit
must be configured for the connected input device using the appropriate
jumper blocks.
Internal batteries, external DC, or a loop current may provide power to
the unit. For all power options other than internal batteries (A), if the
primary power is lost, the internal backup battery will provide for
continued operation of the totalizer.
Once properly wired, the operation of the HIT-2A is automatic.
The flow totalizer is updated every 2 seconds
*
with the latest total. If
no input counts are received the unit remains in a low power state to
conserve power.
The flow total may be cleared by the front panel switch sequence or by
a contact closure on the remote reset terminal to circuit common.
To reset the unit from the front panel, the following key sequence is
required:
Press
P
CLEArtot
is displayed
Press
OK
To enter edit mode.
Press
▲
To select yes
Press
OK
To clear total
Press
▲
To return to operating mode
The flow rate indicator measures the flow rate once every 2 seconds
*
and display the flow rate.
If the input pulses are not detected within the maximum sample time (1
to 80 seconds), a flow rate of zero (0.00) is indicated.
The analog output is scaled based on the user selected zero and full
scale and the measured flow rate.
The pulse output generates a burst of pulses every 2 seconds
*
in
accordance with the instrument setup of pulse scaling.
*
A large sample time setting and internal math operations may delay the
update rate.