10
Chapter 5 Operation
5.1 General
A suitable pulse producing device or fl ow meter is wired to one of the three pulse inputs provided on the DPF500.
Only one of these inputs is used in a given application. There are no connections to the two unused pulse inputs.
Isolated magnetic pickups may be connected to terminals 1 and 2. Isolated contact closures may be connected to
terminals 5 and 6. Any high level, DC
pulse type may be connected to terminals 9(-) and 10(+).
Power to the unit may be provided by internal batteries, external DC, or the current loop. In all cases, the internal
battery will provide for continued operation in the event primary power is lost.
Once properly wired, the operation of the DPF500 is automatic.
The fl ow totalizer is updated once per second* with battery power, instantaneously with DC or loop power. If no
input counts are received the unit remains in a low power state to conserve power.
The fl ow total may be cleared by the front panel switch sequence or by a contact closure on the remote reset ter-
minal to circuit common.
To reset the unit from the front panel, the following key sequence is required:
Press
M
“CLr tot” will be displayed (if the panel lock is on, the display will prompt "
ent code
".
Enter the proper code to advance to the
clr tot
prompt)
Press
E
To clear the total. Unit will return to operation
The fl ow rate indicator will measure the fl ow rate once every second* with battery power, 8 times per second with
DC or loop power and display the fl ow rate.
If the input pulses are not detected within the delay setting (0.1 to 99.9 seconds), a fl ow rate of 0 will be indicated.
The analog output will be scaled based on the user selected zero and full scale and the measured fl ow rate. The
analog output is updated at the same time as the rate display.
The pulse output updates at the same rate as the total display in accordance with the instrument setup of pulse
scaling.
* A large delay setting and internal math operations may delay the update rate. A faster update rate occurs when the
unit is loop powered or externally powered.
5.2 Maintenance
The only scheduled maintenance for the DPF500 is periodic replacement of the battery.
Battery Replacement:
See Section 2.1 for battery installation instructions.
See Section 2.2 for battery replacement instructions.
