7
Hardware Setup
External
Excitation
Internal
1
2
3
4
5
6
7
8
9
10
Figure 4
shows the wiring diagram for the process current input using either internal or external
excitation. The benchtop unit provides 5V excitation by default and can also output 10V, 12V or 24V
excitation voltages. R
efer to the Platinum Series User’s Manual (
) for more information on
selecting the excitation voltage.
Figure 4. 4-20 mA Sensor Wiring Diagram.
Figure 5
shows the wiring for ratio-metric bridge inputs. Connect the resistors R1 and R2, included in the
provided Wire Kit, across terminals 4 and 6 and terminals 1 and 8 respectively. This allows the Bridge
voltage to be measured.
When powering a bridge from the unit use an internal excitation voltage of either 5V or 10V. External
excitation may also be used but must be kept between 3V and 10V and be ground isolated from the
unit.
Figure 5. Bridge Wiring Diagram.
3.3
Universal Thermocouple Connector
The Benchtop Digital Controller accepts
miniature thermocouple connectors. Ensure
the polarity of the connector is correct as
indicated in
Figure 6
. The wide terminal of the
miniature connector is negative.
Figure 6. Thermocouple Input.
1
2
3
4
5
6
7
8
9
10
0
–24 mA
Internal
Excitation
