9 Counter Inputs
The SCADAPack 350 has three counter inputs, identified as Counter 0, 1 and 2. Two of the counter
inputs, Counter 1 and 2, are designed for millivolt level turbine meters. The third, Counter 0, is a
high level digital input for use with open collector/drain output amplifiers.
Refer to the appropriate software manual for information on using the SCADAPack 350 Counter
Inputs in application programs.
• For TelePACE applications use the CNTR Controller Counter Inputs register assignment to
read the counters.
• For ISaGRAF applications use the cntrCtrl I/O connection to read the controller board counters.
• For C applications use the ioReadCounterSP2 function.
9.1 Counter Input 0
Counter Input 0 is used to count contact closures. The input circuitry includes a 1000-ohm resistor
from the counter input to the 5V power supply. Refer to Figure 7: Counter Input Wiring for an
example of wiring to an open collector output.
54321
012
P5 – Counters
GND
Turbine
Meter
Sensor
GND
Turbine
Meter
Amplifier
Consult manufacturer of
amplifier for wiring details.
J9 J10 J11 J12
12 12
Without external amplifier.
Internal amplifier.
With external amplifier.
Dry contact input.
Figure 7: Counter Input Wiring
Counter 1 is shown as a millivolt input with a direct connection to a turbine meter sensor. Note the
use of shielded wiring and that the shield is connected at one end only. Counter 2 is shown
connected to an external turbine meter pre-amplifier. Refer to the following sections for details on
connecting to the turbine meter counter inputs.
9.2 Turbine Meter Counter Inputs 1 and 2
The SCADAPack 350 allows for the direct connection of two turbine meter sensors. These sensors
produce millivolt outputs and do not required to be connected to an additional pre-amplifier when
connecting to a SCADAPack 350. The turbine meter inputs should be used in low noise
environments with shielded cabling.
SCADAPack 350 Hardware Manual
February 14, 2007
25
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