On the other hand, if your amplifier requires a pull-up resistor greater than 1000 ohms, jumper J11
and J12 should not be installed in either position, while J9 and J10 should remain installed as shown
in
The appropriate external pull-up resistor should be should then be connected
between the counter input and the positive terminal of your power supply, as shown in
9.2.3
Connecting to Open Collector / Dry Contact Turbine Meters
Counter Inputs 1 and 2 can also used with conventional sources such as open collector transistors
and contacts. In this scenario, the 1000 ohm pull-up resistors described above can be used if the
SCADAPack 350 is
powered from 12V
.
For Counter 1:
1.
Install jumper J11 in the ‘Ext Position’.
2.
Remove jumpers J9 from the ‘See J11’ position and install on the other two pins.
For Counter 2
3.
Install jumper J12 in the ‘Ext Position’.
4.
Remove jumpers J10 from the ‘See J12’ position and install on the other two pins.
Note:
Note that the above configuration applies only when the controller is being powered using
12V.
If 24V is used to power the controller, the internal 1000 Ohm pull-up resistor should not be used, as
power dissipation can become excessive. In this case, you must wire an external pull-up resistor
between the counter input and the positive side of your power supply, as illustrated in
ensure that jumpers J11 and J12 are removed while J9 and J10 are installed.
J9
J11
Counter 1 input
External pull-up resistor
connected to Input
Voltage
J10
J12
Counter 2 input
External pull-up resistor
connected to Input Voltage
24 V DC
SCADAPack 350
24 V DC
Figure 11: Connecting External Pull-Up Resistors to Counter Inputs 1 and 2
SCADAPack 350 Hardware Manual
February 14, 2007
28
