Modes
The ValveLink8.2 includes several useful features as auxiliary ‘Modes.’
The user changes the current mode settings by pressing the "Mode" button.
The yellow "Set" LED will light. Individual modes are toggled on and off
by pressing their button. The LED associated with each button should
toggle from red to green, with green representing ON. All of the modes
can be used simultaneously, except numbers #2 and #3 which cannot both
be on. Press the "Mode" button to return to normal ValveLink8.2 operation
with any modes activated.
Mode Descriptions
#2
Binary Demultiplexed Addressing Mode
(Valves 1-8 for two ValveLink8.2s)
TTL inputs 1-3 decode into a binary number 0-7 representing which
valve to open (see chart below). Example: TTL input 0000 0101 opens
valve 6 (its decimal equi 1). When this 3-bit number changes, the
previous valve is closed. When Mode #2 or #3 is used, TTL inputs 1-4 are
used for addressing and no longer directly control valves 1-4. For two
ValveLink8.2s, bit 4 is used as described below to further select bank 1 or 2.
Binary chart (showing TTL inputs 4321)
Digital bit pattern
Decimal
Valve
0000
0
1 (d 1)
0001
1 2
0010
2
3
0011
3
4
0100
4
5
0101
5
6
0110
6
7
0111
7
8
1000
8 + 0
1 on second ValveLink8.2
See Mode #3 below.
The only drawback to either addressing mode is that only one valve can
be opened by TTL inputs at a time. Without Mode #2 or #3, each TTL
input corresponds to a single valve and multiple valves can be opened
simultaneously. Because Modes #2 and #3 need several TTL inputs to
select a single valve, only one can be opened in this manner at once. The
ValveLink8.2 will automatically activate Mode #6, "1-On" whenever Mode
#2 or #3 is used.
#3
Addressing Mode - Valves 9-16 (2nd ValveLink8.2)
This is the same binary decoding of bits 1-3 as Mode #2, but bit 4 is used to
select between two ValveLink8.2s and control up to 16 valves with a single
4-bit TTL source. Set the first ValveLink8.2 to Mode #2, set the second to
Mode #3, and connect TTL input bits 1-4 from both ValveLink8.2s to your
digital output. Bits 1-3 decode which valve is opened on the ValveLink8.2
selected by the fourth bit (high = ValveLink8.2 in Mode #3 & low =
ValveLink8.2 in Mode #2). Example: TTL input 0000 1001 opens valve 10
(valve 2 on the second ValveLink8.2.) As in Mode #2, TTL inputs 1-4 are
used for addressing and no longer directly control their respective valves.
BNC "tee" connectors will facilitate connection of BNC cables from two
ValveLink8.2s to a common set of digital outputs.
#4
Pre-selected Valve Mode
When Mode #4 is activated, the user is prompted to select a channel 1-8
when leaving mode selection. All LEDs will flash waiting for a channel
selection. Press "Mode" again to finish. Thereafter, the selected valve is
toggled on and off by TTL input bit #8. This mode allows a researcher to
permanently connect a single TTL output to ValveLink8.2 input eight, and
select which of eight valves to activate with that single TTL signal. This
mode prevents input #8 from controlling valve #8 as it normally would,
unless valve #8 is chosen as the ‘pre-selected’ Mode #4 valve.
#5
Master Valve
When Mode #5 is selected, the user is prompted to select a channel 1-8
when leaving mode selection (like Mode #4 above). This valve then
becomes the master valve. Whenever all other valves have been closed
through pushbuttons or any inputs, the master valve will automatically
open. This feature is useful if a control solution is required whenever all
other solutions are stopped.
#6
One-at-a-time or "1-On" Mode
When active, Mode #6 automatically closes all other valves whenever a
valve is opened – either by pushbutton, TTL, analog or USB input. This
guarantees that no more than one valve is open at a time. This mode is
automatically activated when Mode #2 or #3 is used.
AutoMate Scientific
®
R E A D Y F O R R E S E A R C H.
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