DYNTTS - Commissioning

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Connect cabling and wiring

The figures below show the schematic diagrams of DYNTTS system. Connect both the 9 – 9 pin quadrature cable and the digital CAN cable from the Machine to the AdvDCS unit. Plug the power cables of the machine and AdvDCS unit into the multi-plug adaptor. Then connect the AdvDCS box to the computer via the USB cable supplied.

For Sig 3 upgraded system, Sig 3 controller should be attached to the Actuator Unit. Its CAN cable should be attached from one of the two CANopen ports on the Sig-3 controller to the CANopen port on the Actuator Unit. Finally, a second CANopen cable (supplied) should utilise the remaining CANopen port on the Sig-3 controller and be connected to the AdvDCS unit.

Make the earth connections as per the diagram below. One of the yellow and green earthing cables should run from the machine to the multi-plug adaptor and the other should run from the AdvDCS unit also to the multi-plug adaptor.

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Prepare to power up

Power the controllers on. Install any necessary transducers into the transducer access ring. Plug the transducer cables into the AdvDCS. Power the AdvDCS on. Check that it is running by seeing whether the green LED light at the front of the unit is lit. Press the Emergency STOP button in on the machine. Power on the triaxial machine. – then power on the computer and run GDSLAB. Use the pressure controllers to de-air connections by using their FILL and EMPTY functions. For the Sig 3 controller, go to the docking option in the AdvDCS interface (refer to helpsheet 'AdvDCS User Interface) and select Sig 3 from the ‘Axis’ drop down option. Sig 3 controller can be de-aired by using Retract (Fill) and Extend (Empty) options.

When GDSLAB first runs, you should proceed to the ‘Object Display’ (after selecting the appropriate ini file) – please refer to GDSLAB manual for detailed instructions. Within the Object Display, you must be very careful to ensure that the following parameters are correctly and accurately set.

• Load-cell range and sensitivity*

• Pore pressure range and sensitivity

• Axial controller counts/mm

The ability to change these can be found in the AdvDCS user interface helpsheet.

Once these have been set up you can proceed to checking the functionality of the machine.

Checking machine functionality

This is best done with the front panel removed so that you can observe the position of the ram and see the pulleys and belts moving. Also it is best if this is done without the cell top in place.

First you need to check that the machine is working OK under displacement control. Ensure that the cell chamber is removed from the cell base.

Within the GDSLAB object display, select the MINIDyn displacement control parameter. Set target displacements and see if the ram is moving correctly. You should carefully move the ram until it hits the top limit switch, ensuring you approach the top limit very slowly in case the limit switch is faulty! If the thrust cylinder stop ring gets closer than 1mm to the stop screw then the limit switch position needs adjusting. Carry out the same procedure for the bottom limit switch

Double check the load-cell calibration. To do this put the cell top back on. If you have a little proving ring or known working load cell, use that inside the triaxial cell. If you do not have such a convenient load measuring system then adopt some ad hoc means. For example, you could use the "rubber bung" dummy test specimen described below. You know roughly your own weight. Press your whole weight down onto the dummy test specimen and observe the deformation or ask a colleague to observe it for you. You will now have a rough but very convenient indicator of load.

While the system is set up for displaying readings check that the noise level is low – for example <0.1% of the transducer range.

Position platen

The MINIDyn platen has a nominal stroke of 100mm (normally around 95mm when the software limits are activated). Depending on the expected displacement required for your test, it is sensible to position the platen in a sensible position before replacing the cell top onto your specimen

Move the platen from the GDSLAB ‘Object Display’ to the machines upper and lower limits, this allows you to check the correct operation of the upper and lower axial travel limit switches and to leave the platen at some desired position (say 50%). To do this, click on the AdvDCS icon and navigate to the ‘Docking’ tab. This enables the user to move the machine in the positive ('Extend') or negative ('Retract'). The speed at which the platen moves can also be defined from this tab.