Athena III User Manual Rev A.03
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Page
34
7.4
RS-232/422/485 Termination Select (JP7)
Jumper block JP7 is used to configure RS-232/422/485 termination selection.
7.5
Data Acquisition Configuration (J26)
Jumper block J26 is used to configure the A/D and D/A circuits
.
Jumper Label
Configuration Function
SE/DIFF
A/D single-ended/differential selection.
AD UNIPOL
A/D unipolar/bipolar selection.
7.5.1
Single-Ended/Differential Input Settings
Athena III 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 III) 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
J26 Jumper Block
JP7 RS-232/422/485 Default Jumper Settings