Jumper Label
Configuration Function
SE/DIFF
A/D single-ended/differential selection.
AD UNIPOL
A/D unipolar/bipolar selection.
DA SEL
D/A unipolar/bipolar selection.
Single-ended/Differential Input Settings
Athena II can accept both single-ended and differential inputs. A single-ended input uses two wires: input and
ground. The measured input voltage is the difference between these two wires. A differential input uses three
wires: input(+), input(–) and ground. The measured input voltage is the difference between the (+) and (–) inputs.
Differential inputs are frequently used either when the grounds of the input device and the measurement device
(Athena II) are at different voltages, or when a low-level signal is being measured that has its own ground wire. A
differential input also has higher noise immunity than a single-ended input because most noise affects both (+) and
(–) input wires equally, so the noise is canceled out in the measurement. The disadvantage of differential inputs is
that only half as many are available because two input pins are required to produce a single differential input.
Athena II can be configured for either 16 single-ended inputs, or eight differential inputs, as shown below. The
default setting is single-ended mode.
If you have a combination of single-ended and differential input signals, select differential mode. Then, to measure
the single-ended signals, connect the signal to the plus (+) input and connect analog ground to the minus (–) input.
WARNING: The maximum range of voltages that can be applied to an analog input on Athena II
without damage is ±35V. If you connect the analog inputs on Athena to a circuit whose ground
potential plus maximum signal voltage exceeds ±35V, the analog input circuit may be damaged.
Check the ground difference between the input source and Athena II before connecting analog input
signals.
Unipolar/Bipolar Input Settings
The analog inputs can be configured for either unipolar (positive input voltages only), or bipolar (both positive and
negative input voltages). For unipolar inputs, install a jumper as shown below. For bipolar inputs, omit the jumper.
The default configuration is bipolar mode (jumper out).
Analog Output Configuration Settings
Diamond Systems Corporation
Athena II User Manual
Page 37
Figure 25: A/D Unipolar/Bipolar Selection
Figure 24: A/D Single-ended/Differential Selection
