This manual outlines how to operate the vibration stimuli in the MWP Z3 model. If you have an earlier Z2 or Z2S model please see the vibration demo page for the Z2 or Z2S system
The Zantiks MWP Z3 system has two different ways of providing a vibration stimuli within the vibration plate.
The two types of vibration include:
- Stepper motor - Allows control of strenght, frequency & duration
- Eccentric Rotating Mass (ERM) buzzer - Smooth vibration which can be set to low, medium or high
Stepper motor
The stepper motor has 200 steps to make a full rotation. However, the motor is mounted such that it cannot rotate freely. By attempting to rotate, the motor moves the layer for the MWP Z3 system that a multi-well plate or petri dish rests on. As such the attempted turns of the stepper motor can pass vibrations to the test organism(s).
The built-in stepper motor and is controlled using the following operation commands within a ZCOMMAND.
'U' Step mode (0-3, for full/half/quarter/eighth step modes) 'D' Delay between motor steps (to set motor speed - should not be below 1000) 'M' Number of Motor steps (e.g., 200, -50) 'P' Pause, to set delay between operations (ms)
- "M" operation command controls the number of 'steps' the motor rotates. To rotate the motor a full 360 degrees, the number following M would be 200.
- "D" operation command tells the unit the delay between each step. This is in units of 4.25 µsecs.
- The "U" operation command tells the unit how large each step should be. The operations available are 0-3. "U0" is a full step, "U1" is a ½ step, "U2" is a ¼step, "U3" is an ⅛ of a step.
- If the step mode at a full step (U0), and the motor is set to move 200 steps (M200) the motor will rotate a full cycle. If the step mode is set to a ½ step (U1), 400 steps (M400) are required to rotate a full cycle.
- The smallest step mode (U3) has the smallest vibration
- "P" operation command is used to add a delay in milliseconds between operation commands (e.g., motor movements). It can be used between any of the other parameters below.
Some example ZCOMMANDs for driving the motor for the vibration plate in the MWP system are shown below.
ZCOMMAND("D2500 U0 M1000")
ZCOMMAND("D2500 U1 M1000")
ZCOMMAND("D2500 U2 M1000")
ZCOMMAND("D2500 U3 M1000")
ZCOMMAND("D1000 U0 M2000 P100 M-2000")
Frequency Calculator for Vibrations in the MWP
Download the spreadsheet below to calculate the "D" command value needed for a desired frequency or the frequency created from a specified "D" command value.
ERM motor
The Eccentric Rotating Mass(ERM) motor is also attached to the same layer as the stepper motor. An ERM motor uses an asymmetrical, off-center weight attached to a spinning shaft. When power is applied to the motor, the spinning unbalanced weight creates an uneven centrifugal force. The rapid wobbling transfers through to the vibration layer which the multi-well plate or petri dish rests on and creates a vibration. The ERM vibration was designed for arousing Drosophila flies from sleep.
The ERM vibration is controlled using a GPO command. GPO6, 7 or 8 can be used for a strong, medium or weak stimuli respectively. This can be used within a ZCOMMAND or just with the GPO commands.
Using a ZCOMMAND allows use of the Pause feature (P) which allows you to set a wait time in milliseconds e.g.
ZCOMMAND("G6#1 P1000 G6#0") # high vibration
ZCOMMAND("G7#1 P1000 G7#0") # medium vibration
ZCOMMAND("G8#1 P1000 G8#0") # low vibration
In the above commands G*#1 starts the ERM vibration at etiher high, medium or low strength. P pauses for 1000 milliseconds. G*#1 turns of the vibration.
The ZCOMMAND can also be used to set off a sequence of vibrations. e.g.
ZCOMMAND("G6#1 P500 G6#0 P500 G7#1 P500 G7#0 P500 G8#1 P500 G8#0 P500 ")
The above command runs through a high, medium and low vibration with a pause of 500ms in between.
Alternatively the GPO commands can be used with a wait command. E.g.
SET(GPO6,1) WAIT(1) SET(GPO6,0)
Turns on the ERM vibration at the strongest setting, waits 1 second, then turns the vibration off
SET(GPO7,1) WAIT(1) SET(GPO7,0)
Turns on the ERM vibration at the medium setting, waits 1 second, then turns the vibration off
SET(GPO8,1) WAIT(1) SET(GPO8,0)
Turns on the ERM vibration at the lowest setting, waits 1 second, then turns the vibration off
Script explanation
Below we have an example script which can be copied and pasted into a Zanscript to run vibration stimuli in the MWP system using both the stepper motor and the ERM, followed by an explanation of the code. It is recommended that you test different vibration settings to see which ones are the best for your experiments.
ACTION MAIN
#Stepper motor
ZCOMMAND("U0 D1000 M10 M-10")
WAIT(2)
ZCOMMAND("U1 D1000 M10 M-10")
WAIT(2)
ZCOMMAND("U2 D1000 M10 M-10")
WAIT(2)
ZCOMMAND("U3 D1000 M10 M-10")
WAIT(2)
ZCOMMAND("U0 D1000 M1 M-1 M1 M-1 M1 M-1 M1 M-1 M1 M-1")
WAIT(2)
ZCOMMAND("U1 D1000 M1 M-1 M1 M-1 M1 M-1 M1 M-1 M1 M-1")
WAIT(2)
ZCOMMAND("U2 D1000 M1 M-1 M1 M-1 M1 M-1 M1 M-1 M1 M-1")
WAIT(2)
ZCOMMAND("U3 D1000 M1 M-1 M1 M-1 M1 M-1 M1 M-1 M1 M-1")
WAIT(2)
#ERM motor
ZCOMMAND("G6#1 P1000 G6#0")
WAIT(2)
ZCOMMAND("G7#1 P1000 G7#0")
WAIT(2)
ZCOMMAND("G8#1 P1000 G8#0")
WAIT(2)
SET(GPO6,1)
WAIT(2)
SET(GPO6,0)
WAIT(2)
SET(GPO7,1)
WAIT(2)
SET(GPO7,0)
WAIT(2)
SET(GPO8,1)
WAIT(2)
SET(GPO8,0)
WAIT(2)
COMPLETE
The above action programs the unit to deliver a range of different sized vibratory stimuli using the ZCOMMAND and/or GPO commands for both the stepper motor and the ERM.
For the stepper motor:
- The "U" command tells the unit how big each step should be, where "U0" is a full step (i.e. 1.8 degrees), "U1" is a half step (0.9 degrees), "U2" is a quarter step (0.45 degrees), "U3" is an eighth of a step (0.225 degrees).
- The "D" command controls the total amount of 'delays' between each step. Delays are in units of 4.25 µsecs (0.00000425 seconds). Therefore, for D2000, there are 2000 'delays' of 4.25 µsec between steps, which translates to a frequency of 1/(2000 x 0.00000425), 118Hz.
- The "M" command programs how many steps the motor rotates. In the first 4 ZCOMMANDS the motor will rotate 10 steps clockwise. In the last 4 ZCOMMANDS the motor will rotate 1 step clockwise and 1 step anticlockwise for a total of 10 steps. This can provide a smaller but smoother stimuli than using M10. The greater the number of "M's" the longer the vibration. Multiple commands in the same direction often lead to slippage of the stepper motor (as it is prevented by its mounting from turning all the way), and bigger vibrations, but they are not strictly repeatable / consistent. We recommend always using the M1 M-1 option for writing vibration stimuli so that the motor position is always reset at the end of each stimulus, this leads to better consistency.
For the ERM motor GPO6 is the strongest vibration, GPO7 in the medium vibration and GPO8 is the weakest vibration.
Script download
To download the vibration_demo_MWP demo scripts as .zs files (file type Zantiks software reads), choose the Save File As option in the right-click dialogue box. Clicking on the script name hyperlink will open a read-only version of the script.
