E9Screen Software
EPC9 Manual
39
AD-Channel
: The oscilloscope can display the following:
• F2-Ext
- External Stim. Input filtered by Filter 2
• Imon-1
- Current monitor 1
• Imon-2
- Current monitor 2
• Vmon
- Voltage monitor output
• AD 0…5
- Any of the other AD channels.
The
F2-Ext
setting allows you to use Filter 2 as a general-purpose variable filter. In
this setting the
External Stim Input
becomes the filter input, and the filter output is
available at Filter 2 and is displayed in the
Oscilloscope
window.
Help
: Displays keyboard equivalents that are assigned to EPC9 controls.
In this mode you can click on any control to have the
Help
window
display a short description of that control.
Sound
: If this control is
On
, a sound is played with
its frequency coding for
R-membrane
. The sensitivity
(Hz/M
Ω
) and the volume can be specified. The
controls that set these parameters are normally
hidden, but may be accessed by closing the
Oscilloscope
window.
V
0
(
Pipette Offset
):
V
0
displays the offset
voltage (a voltage which is added to
V-
membrane
to obtain the pipette command voltage). It can be set either by the
Auto-V
0
operation or by manually dragging the mouse after clicking into the item.
Furthermore,
V
0
is changed automatically by the controlling program whenever the
user changes the variable
LJ
. This is necessary for
LJ
and the
Auto-V
0
operation to
interact properly. It is not recommended that the user changes
V
0
manually, because
this interferes with the software features for automatic offset correction.
Auto-V
0
: The
Auto-V
0
button calls a procedure for automatic zeroing of the pipette
current. Thereby, an offset voltage (
V
0
) to the pipette potential is systematically
varied until pipette current is zero. Range of
V
0
is ± 200mV.
Auto-V
0
is typically
performed before seal formation. It works properly only when a pipette is inserted
into the bath.
The
Auto-V
0
procedure interacts with the variable
LJ
to provide for online correction
of liquid junction potentials and other offsets (see
Chapter
7. Compensation
Procedures
on page 59
). This requires that
V-membrane
is set to the value of
LJ
(for
On
Cell
and
In Out
Recording Modes) or to the opposite polarity of
LJ
(for
Whole Cell
and
