7.1.4 Grounding terminals
Proper grounding lends stability and protection to a data acquisition system. It is the easiest and
least expensive insurance against data loss — and often the most neglected. The following
terminals are provided for connection of sensor and VOLT 100 series grounds:
l
Signal Ground (
⏚
) – reference for single-ended analog inputs, excitation returns, and as a
ground for sensor shield wires. Current loop sensors, however, should be grounded to
power ground.
l
Power Ground (G) – return for 5V, 12V, and current loop sensors. Use of G grounds for
these outputs minimizes potentially large current flow through the analog-voltage-
measurement section of the wiring panel, which can cause single-ended voltage
measurement errors.
l
Earth Ground Lug (
⏚
) – connection point for a heavy-gage earth-ground wire. A good
earth connection is necessary to secure the ground potential of the VOLT 100 series and
shunt transients away from electronics. 14 AWG wire, minimum, is recommended.
NOTE:
Several ground wires can be connected to the same ground terminal.
7.1.5 Power terminals
7.1.5.1 Power in
The removable Power connector is the connection point for external power supply components.
The power supply must be in the range of 9.6 to 32 VDC.
7.1.5.2 Power out
The VOLT 100 series can be used as a power source for sensors. The following voltage terminals
are available:
l
12V and SW12V – Regulated 12 VDC when the supply voltage is 14.5 to 32 VDC. Below 14.5
VDC, the voltage tracks the power supply. Current output is limited to 200 mA.
l
SW5V – See
(p. 20) for information on voltage and current sourcing limits.
7.1.6 Communications ports
One micro-B USB port, labeled USB, is for communicating with a computer through SURVEYOR
or Device Configuration Utility software.
VOLT 100 series
13
