GPI SC510 Guía De Operación página 4

W I R I N G D I A G R A M 1
Sine Wave Input from A1, G2 or G Series
Note: Pull-up resistor only required if not supplied by receiving equipment.
W I R I N G D I A G R A M 2
Open-Collector, Hall Effect, RF, Active Drive
From G2, GM, IM or G Series
High Level, High Frequency Input
Note: Pull-up resistor only required if not supplied by receiving equipment.
W I R I N G D I A G R A M 3
High Level, Low Frequency Input
Contact Closure or Reed Switch from GM and IM Series
Note: Pull-up resistor only required if not supplied by receiving equipment.
4
The GPI Scaled-Pulse circuit contains input condition-
ing, with circuit protection, for the three most commonly
found flowmeter signal-output types:
Coil Input:
• This input accepts a low level or "sine wave" signal
OC OUT
from almost any magnetic pickup coil.
COM
• Signal amplitude must be greater than 25 mV p-p
(peak-to-peak), and have only a single "rising edge"
and a single "falling-edge" per cycle.
• The Coil Signal Input should not exceed 1 V p-p in
amplitude.
• Do not connect either of the Coil Input lines to any
ground point.
NOTE: In applications with very low p-p voltage, shielded
cable may be required (to reduce electrical "noise"
pickup) between the pickup coil and the input
terminal. If a cable shield is used, connect only
the circuit end to any of the COM terminals. Do
not connect the shield to anything at the pickup
coil end.
High Level, High Frequency:
• This input accepts a signal from either an open-
collector device (there is a built-in "pull-up" resistor
at this input), or an active-drive device (sometimes
OC OUT
called a "square wave"). Such signals usually come
COM
from either a "pre-amp" or some type of "active"
pickup device (such as a Hall Effect or RF Sensor).
• If open-collector, the correct signal amplitude will
automatically be applied by the GPI circuit.
• If active-drive, the minimum required signal ampli-
tude is 2 V p-p. The maximum active-drive signal
amplitude should be restricted to no more than about
25 V p-p.
NOTE: The High Level, High Frequency input is not
"de-bounced." Do not connect a switching device
(such as a Reed Switch) to this input.
High Level, Low Frequency:
• This input accepts a contact-closure type pickup
device, such as a Reed Switch.
• Maximum upper frequency is restricted to about
150 Hz.
• The input is internally "debounced" so that it will cor-
OC OUT
rectly process a contact-closure type pickup device,
COM
such as a Reed Switch.
• Otherwise, the input generally has the same form
and specifications as the High Level, High Frequency
input described above.
NOTE: No additional components are usually required,
since the GPI circuit contains a built-in "pull up"
resistor at this input.
INPUT(S)