©
National Instruments Corp.
19
NI 9853 Operating Instructions
Safety
Maximum Voltage
1
Connect only voltages that are within these limits.
Port-to-COM..................................... –27 to +40 VDC max,
Measurement Category I
Measurement Category I is for measurements performed on
circuits not directly connected to the electrical distribution system
referred to as
MAINS
voltage. MAINS is a hazardous live electrical
supply system that powers equipment. This category is for
measurements of voltages from specially protected secondary
circuits. Such voltage measurements include signal levels, special
equipment, limited-energy parts of equipment, circuits powered by
regulated low-voltage sources, and electronics.
Caution
Do not connect to signals or use for
measurements within Measurement Categories II, III,
or IV.
1
The maximum voltage that can be applied or output between any port or V
SUP
terminal and a COM terminal without creating a safety hazard.
