NOVA
MUX Tutorial
Version 1.11.0
NOVA MUX tutorial
1 – The MUX module
The MUX is an optional module for the Autolab PGSTAT and the Multi Autolab.
With the MUX module, it is possible to multiplex the PGSTAT electrode
connections 1. Depending on the type of MUX used, measurements on several
electrochemical cells or working electrodes can be done sequentially.
The MUX module is available in three standard configurations:
•
MUX-MULTI4: in this configuration, the WE, S, RE and CE leads from the
PGSTAT are multiplexed to 4 (or more) sets of connections (see Figure 1).
This means that sequential measurements can be performed on multiple
independent electrochemical cells. It is possible to add up to 16 MUXMULTI4 boxes in series in order to multiplex up to 64 independent
electrochemical cells.
WE1
WE2
WE3
WE4
S1
S2
S3
S4
CE1
CE2
CE3
CE4
RE1
RE2
RE3
RE4
MULTI4
Figure 1 – The MUX-MULTI4 box
Note
The MUX-MULTI4 is typically used for sequential measurements on individual
electrochemical cells or for measurements requiring different electrode
arrangements in the same cell (like Van der Pauw measurements).
•
MUX-SCNR8: in this configuration, the RE and S leads from the PGSTAT are
multiplexed to 8 (or more) sets of connections (see Figure 2). This means that
the differential amplifier of the PGSTAT can be multiplexed across as many
While the MUX module has been designed to multiplex the connections provided by the Autolab
PGSTAT, it can be used to multiplex other connections (like the pX module input for example).
1
2|Page
NOVA MUX tutorial
individual cells. It is possible to add up to 16 MUX-SCNR8 boxes in series in
order to multiplex up to 128 sets of RE and S electrodes.
RE1
RE2
RE3
RE4
S1
S2
S3
S4
RE5
RE6
RE7
RE8
S5
S6
S7
S8
SCNR8
Figure 2 – The MUX-SCNR8 box
Note
The MUX-SCNR8 is intended to be used for measurements on individual cells in
a series of cells. The most common example is the measurement of cell voltages
of individual cells or sections of cells in a fuel cell stack.
•
MUX-SCNR16: in this configuration, the WE lead from the PGSTAT is
multiplexed to 16 (or more) WE connections (see Figure 3). This means that
sequential measurements can be performed on multiple working electrodes
sharing a common reference electrode and counter electrode. It is possible
to add up to 16 MUX-SCNR16 boxes in series in order to multiplex up to 255
working electrodes.
3|Page
NOVA MUX tutorial
WE1
WE2
WE3
WE4
WE5
WE6
WE7
WE8
WE9
WE10
WE11
WE12
WE13
WE14
WE15
WE16
SCNR16
Figure 3 – The MUX-SCNR16 box
Note
The MUX-SCNR16 is intended to be used for measurements on individual
working electrodes contained in a single electrochemical cell. Corrosion and
sensor measurements usually benefit from this hardware extension.
The MUX boxes can be connected in series up to a maximum of 16 boxes, as shown
in Figure 4.
To MUX module in PGSTAT
WE1
WE2
WE3
WE4
WE1
WE2
WE3
WE4
WE1
WE2
WE3
S1
S2
S3
S4
S1
S2
S3
S4
S1
S2
S3
S4
CE1
CE2
CE3
CE4
CE1
CE2
CE3
CE4
CE1
CE2
CE3
CE4
RE1
RE2
RE3
RE4
RE1
RE2
RE3
RE4
RE1
RE2
RE3
RE4
MULTI4
MULTI4
Channels 1-4 (MULTI4)
Channels 1-8 (SCNR8)
Channels 1-16 (SCNR16)
MULTI4
Channels 5-8 (MULTI4)
Channels 9-16 (SCNR8)
Channels 17-32 (SCNR16)
To Cell cables PGSTAT
(RE, S, WE and CE for MULTI4)
(WE/S for SCNR16, RE/S for SCNR8)
Figure 4 – Up to 16 MUX boxes can be connected in series
Note
The MUX boxes must all be of the same type.
4|Page
Additional channels
WE4
NOVA MUX tutorial
Scope of the tutorial
The aim of this tutorial is to explain how to use the MUX module to multiplex the
connections provided by the Autolab. The use of the manual control and
automatic control of the MUX is illustrated using the dummy cell.
At any time, one of the available MUX channels can be activated manually or
automatically in the software. The MUX can be used for all electrochemical
techniques.
Caution
The MUX modules cannot be used in combination with the Autolab PGSTAT100N
or PGSTAT100 and the PGSTAT302F. It is also not possible to use the MUX
modules in combination with the Booster10A or the Booster20A.
2 – Hardware setup
In order to use the MUX module, the hardware setup in NOVA must be configured
accordingly (see Figure 5).
Figure 5 – Selecting the MUX module
5|Page
NOVA MUX tutorial
The number of available channels can be defined in the frame on the right-hand
side of the hardware setup window (see Figure 5). This value corresponds to the
maximum number of channels available for instrument.
3 – Manual control of the MUX module
The MUX module can be controlled manually at any time, using a dedicated panel
of the Autolab display. To add the MUX manual control panel to the Autolab display,
select the MUX manual control option from the View menu (see Figure 6).
Figure 6 – Select the MUX manual control option from the View menu to add the MUX
control panel to the Autolab display
The MUX manual control panel will be shown whenever the Autolab display is
displayed (see Figure 7). Select the Autolab display option from the View menu or
press the F10 shortcut key to show the Autolab display.
6|Page
NOVA MUX tutorial
Figure 7 – The MUX manual control panel
The MUX manual control can be used to set the active channel of the MUX. It also
displays the currently active channel. In Figure 7, the active channel is 1 and a total
of 4 channels are available. The number of available channels depends on the
hardware setup. Figure 7 corresponds to the hardware setup shown in Figure 5.
Note
When the active channel is set to 0, none of the MUX channels are used.
Using the manual control, it is possible to switch to any of the available channels by
typing the corresponding value in the Select [0..X] field 2 and pressing the
button (see Figure 8). Alternatively, the
buttons can be used to increase or
decrease the channel number.
2
X is the number of available channels – see hardware setup.
7|Page
NOVA MUX tutorial
Figure 8 – Switching MUX channels
Note
The new channel is activated as soon as the
button is clicked.
4 – Automatic control of the MUX module
Control of the MUX module during a measurement is also possible using the Autolab
control command. The channel number control of the MUX module is available in
the Autolab control window, on the MUX section (see Figure 9).
8|Page
NOVA MUX tutorial
Figure 9 – The Autolab control window can be used to control the MUX channel
The Autolab control can be used at any time during a measurement to change the
MUX channel automatically. The selected MUX channel is shown in the procedure
editor, below the Autolab control command used to define its value (see Figure 10).
Figure 10 – The selected MUX channel is displayed below the Autolab control
The MUX(1).Channel parameter shown below the Autolab control command in the
procedure editor can also be linked to other parameters, like an input box command
or a repeat for each value loop.
9|Page
NOVA MUX tutorial
5 – Measurements with the MUX module on the dummy cell
A MUX tutorial folder is located in the Program Files\Metrohm Autolab\Nova
1.11\Shared Databases\Tutorials folder (see Figure 11). Using the database
manager, set this folder as the Standard database.
Figure 11 – Loading the MUX tutorial database
The MUX tutorial contains three procedures (see Figure 12). Both procedures
illustrate the use of the Autolab control command to switch MUX channels during
a measurement. These procedures are to be used on the Autolab dummy cell.
Figure 12 – The two MUX tutorial procedures
Depending on the hardware configuration, the connection between the MUX and
the dummy cell should be as displayed in Figure 13 for the MUX-MULTI4
configuration, in Figure 14 for the MUX-SCRN8 or as in Figure 15 for the MUXSCNR16.
10 | P a g e
NOVA MUX tutorial
C1
1µF
R2
CE
WE(+S)
(a)
R4
100Ω
1MΩ
CE1
CE2
C2
1µF
R1
RE
R3
100Ω
S1
WE2
S2
1MΩ
R7
10kΩ
RE1
RE2
WE1
WE(+S)
(b)
1µF
C3
WE(+S)
(e)
R5
WE(+S)
(c)
1kΩ
C4 R6
1µF 5kΩ
WE(+S)
(d)
DUMMY CELL2
Figure 13 – Overview of the connections to the dummy cell when using the MUX-MULTI4
C1
1µF
R2
CE
100Ω
WE(+S)
(a)
R4
1MΩ
CE
C2
RE
100Ω
RE2
R7
10kΩ
RE1
S1
S2
WE(+S)
(b)
R3
1MΩ
C3
WE(+S)
(e)
WE
1µF
R1
R5
1µF
WE(+S)
(c)
1kΩ
C4 R6
1µF 5kΩ
WE(+S)
(d)
DUMMY CELL2
Figure 14 – Overview of the connections to the dummy cell when using the MUX-SCNR8
11 | P a g e
NOVA MUX tutorial
C1
1µF
R2
CE
100Ω
WE(+S)
(a)
R4
1MΩ
CE
C2
100Ω
R7
10kΩ
RE
WE(+S)
(b)
R3
1MΩ
C3
WE(+S)
(e)
WE1
1µF
R1
RE
R5
1µF
WE(+S)
(c)
1kΩ
WE2
C4 R6
1µF 5kΩ
WE(+S)
(d)
DUMMY CELL2
Figure 15 – Overview of the connections to the dummy cell when using the MUX-SCNR16
Note
In the SCNR16 connect both the WE and the S from the PGSTAT to the WE input
of the SCNR16.
5.1 – MUX tutorial 1 – Control of the MUX through an Input box
Load the MUX tutorial 1 procedure. Figure 16 shows an overview of the procedure.
An Input box is located in between the two Timed procedure commands. The value
of the input is linked to the MUX(1).Channel parameter located in the Autolab
control command.
12 | P a g e
NOVA MUX tutorial
Figure 16 – The MUX tutorial 1 procedure
Connect the MUX to the dummy cell according to one of the schemes shown in
Figure 13 or Figure 15 and press the Start button. A message box will be displayed
at the beginning of the experiment (see Figure 17).
Figure 17 – A message box is displayed at the beginning of the measurement
Click the OK button to continue. A cyclic voltammetry measurement will be
performed on the channel 1 of the MUX. During this experiment, the data is
displayed on plot number 1 in the measurement view (see Figure 18).
13 | P a g e
NOVA MUX tutorial
Figure 18 – MUX tutorial measured data part 1 – MUX Channel 1 data on plot #1
At the end of the first measurement, an input box will be displayed (see Figure 19).
This input box can be used to set the next value of the MUX channel. For this tutorial
procedure, the value should be 2.
Figure 19 – An input box is displayed at the end of the first measurement
Click OK to continue. The MUX will be switched to channel 2 and the same
measurement will be repeated. The data is plotted on plot number 2 in the
measurement view (see Figure 20).
Note
Switch the measurement view to Two plots vertically tiled mode by pressing the
button in the toolbar.
Note
The data shown in Figure 20 corresponds to the data obtained with the MUXMULTI4 or the MUX-SCNR16.
14 | P a g e
NOVA MUX tutorial
Figure 20 – MUX tutorial measured data part 2 – MUX Channel 1 data on plot #1 (blue
curve) and MUX Channel 2 data on plot #2 (red curve)
The measured data depends on the hardware configuration.
•
•
MUX-MULTI4 or MUX-SCNR16: Since MUX Channel 1 is connected to
dummy cell (a) and MUX Channel 2 is connected to dummy cell (c), the
WE(1).Current values vary between ± 1 µA and ± 0.9 mA, respectively.
MUX-SCNR8: Since MUX Channel 1 and 2 are connected to dummy cell (a)
the WE(1).Current values vary between ± 1 µA on both plots.
5.2 – MUX tutorial 2 – Control of the MUX through the Autolab control
command
Load the MUX tutorial 2 procedure. Figure 21 shows an overview of the procedure.
At the beginning of the experiment, an Autolab control command is used to set the
MUX channel to 1. An additional Autolab control is used to switch from channel 1
to channel 2 after the first measurement.
Figure 21 – The MUX tutorial 2 procedure
15 | P a g e
NOVA MUX tutorial
Connect the MUX to the dummy cell according to one of the schemes shown in
Figure 13 or Figure 15 and press the Start button. A message box will be displayed
at the beginning of the experiment (see Figure 22).
Figure 22 – A message box is displayed at the beginning of the measurement
Click the OK button to continue. A cyclic voltammetry measurement will be
performed on the channel 1 of the MUX. During this experiment, the data is
displayed on plot number 1 in the measurement view (see Figure 23).
Figure 23 – MUX tutorial measured data part 1 – MUX Channel 1 data on plot #1
At the end of the first measurement, the MUX will switch the active channel to
channel 2 automatically. The same measurement will be repeated and the data is
plotted on plot number 2 in the measurement view (see Figure 24).
Note
The data shown in Figure 24 corresponds to the data obtained with the MUXMULTI4 or the MUX-SCNR16.
16 | P a g e
NOVA MUX tutorial
Figure 24 – MUX tutorial measured data part 2 – MUX Channel 1 data on plot #1 (blue
curve) and MUX Channel 2 data on plot #2 (red curve)
The measured data depends on the hardware configuration.
•
•
MUX-MULTI4 or MUX-SCNR16: Since MUX Channel 1 is connected to
dummy cell (a) and MUX Channel 2 is connected to dummy cell (c), the
WE(1).Current values vary between ± 1 µA and ± 0.9 mA, respectively.
MUX-SCNR8: Since MUX Channel 1 and 2 are connected to dummy cell (a)
the WE(1).Current values vary between ± 1 µA on both plots.
5.3 – MUX tutorial 3 – Control of the MUX through the Repeat for each value
command
Load the MUX tutorial 3 procedure. Figure 25 shows an overview of the procedure.
The measurement is now located inside a Repeat for each value command. The
values defined in the repeat loop are linked to the MUX channel in the Autolab
control command. The measurement is first performed on channel 1 and then on
channel 2.
Figure 25 – The MUX tutorial 3 procedure
17 | P a g e
NOVA MUX tutorial
Connect the MUX to the dummy cell according to one of the schemes shown in
Figure 13 or Figure 15 and press the Start button. A message box will be displayed
at the beginning of the experiment (see Figure 26).
Figure 26 – A message box is displayed at the beginning of the measurement
Click the OK button to continue. A cyclic voltammetry measurement will be
performed on the channel 1 of the MUX. When the measurement is finished, the
cell is switched off, and channel 2 is selected. The same experiment is repeated. The
data is plotted on plot number 1 in the measurement view (see Figure 27).
Note
The data shown in Figure 27 corresponds to the data obtained with the MUXMULTI4 or the MUX-SCNR16.
Figure 27 – MUX tutorial measured data
18 | P a g e
NOVA MUX tutorial
The measured data depends on the hardware configuration.
•
•
MUX-MULTI4 or MUX-SCNR16: Since MUX Channel 1 is connected to
dummy cell (a) and MUX Channel 2 is connected to dummy cell (c), the
WE(1).Current values vary between ± 1 µA and ± 0.9 mA, respectively.
MUX-SCNR8: Since MUX Channel 1 and 2 are connected to dummy cell (a)
the WE(1).Current values vary between ± 1 µA on both plots.
Both cyclic voltammograms are shown on the same plot.
19 | P a g e
NOVA MUX tutorial
Hardware specifications
The MUX module is available in three versions:
•
•
•
MUX-MULTI4: can be used to multiplex all four electrodes provided by the
Autolab: CE, RE, S and WE. Using this module, it is possible to work on
different electrochemical cells, sequentially.
MUX-SCNR8: can be used to multiplex two independent electrodes
provided by the Autolab. The most common use of this special module is to
multiplex the S and RE connection from the differential amplifier in order to
measure the potential difference across several electrochemical interfaces,
sequentially.
MUX-SCNR16: can be used to multiplex a single electrode provided by the
Autolab. The most common use of this module is to multiplex the S+WE in
order to perform electrochemical measurements on different working
electrodes located in the same cell, sharing the counter and reference
electrode. The measurements are performed sequentially.
Table 1 provides an overview of some of the MUX module specifications.
Module
Number of channels
Increment per extension
Switching time
Maximum current
MULTI4
4-64
4
5 ms
2A
SCNR16
16-255
16
5 ms
2A
SCNR8
8-128
8
5 ms
2A
Table 1 – Overview of the specifications of the MUX modules
Note
Inactive MUX channels are kept at open circuit potential at all times.
Caution
The MUX modules cannot be used in combination with the Autolab PGSTAT100N
or PGSTAT100 and the PGSTAT302F. It is also not possible to use the MUX
modules in combination with the Booster10A or the Booster20A.
20 | P a g e