Servo Hydraulic Systems FAQ

This problem has been fixed in Series IX V8.27 (Suite 11094). Install this or a later version to resolve this.
A workaround is shown below: This procedure will enable a user to run an 8500/8800 with an HRDE: 1. Run setup in Series IX and choose some 4400 machine and set extensometer to HRDE. 2. Go into the method editor and set up everything as best you can for the 8800. 3. Exit Series IX. This will set the instron.ini file correctly. Just to make sure, check that the [SERIESIX] section has: AUTOEXT=HRDE EXTGPIB=01 (or whatever GPIB address you are using) 4. Load up Series IX again. 5. Run setup and choose the proper 8800 machine. 6. Go into the method editor and check all the fields in your method. You won't see HRDE, but make sure everything else is OK. If you don't need to change anything, just exit WITHOUT saving the method. 7. If you needed to change anything in step 6, save the method, but then you need to do this extra step: With any text editor such as Notepad, edit mt?oprNN.def. (? is a for tensile, b for flex, c for compression, and d for yarn/fiber, and NN is the number of your method.) In the entry that starts with EX, change the first parameter to 3.0. This will make the 8800 use the HRDE, since the code is all still there, and will use it once it reads the 3.0 parameter from the EX line, which tells it that an HRDE is enabled.

Note: Adaptive control and commissioning only applies to 8500 Plus version 35 or 37, and all versions of 8800. The system first has to be commissioned and then it has to be auto-tuned. (Consult your operator's manual.)

Press the function switch and then the switch under where it says "Select Units" in the basic display. Press the switch under where it says "SI, METRIC or US CUSTOMARY" for the units you prefer to test in.

Note: Commissioning only applies to 8500 Plus version 35 or 37, and all versions of 8800. Consult your Operator's Manual for instructions on issuing a GPIB command.>/li> Calculate a value of Ka (stiffness) as described below and enter the result using the following GPIB command: C606,2,value. It is then necessary to tell the system that commissioning is complete by sending GPIB command C612,1. The stiffness of the linear actuator is calculated by the formula: Ka=11700 x Fst / S x Ps Where Fst is the actuator stall force in KN, S is the actuator working stroke +-mm, Ps is the supply pressure in bar (3000 psi = 207 bar). Example: A +-50mm stroke actuator with a stall force of 120kN and a supply pressure of 207 bar has a stiffness of: Ka=11700 x 120/50 x207 = 135.6 KM/mm.

Press the “SET-UP” switch on the strain 1 or strain 2 panel on the MMI. The lower display will show the strain units in either displacement or percent elongation. If it is in displacement press the switch on the left below the basic display, press the “more” switch and than press the switch under %. This will change the units to percent elongation. Next, press the second switch from the left below the basic display. The display will show the present gauge length. To change the gage length press the switch under the gauge length value and enter the new gauge length. Once the new gauge length is entered press the enter switch on the keyboard.

Push the following switches on the control panel: 1. Function 2. Instron Service 3. Continue 4. System Version If using Fast Track 2 Console, left mouse click on the Actuator in the upper right corner of the Test Toolbar. The Firmware version will be displayed on the screen that appears with the General tab. If using RS Console, left click on the Axis Name, then select the General tab. The Firmware version will be displayed on the screen that appears with the General tab.

An external waveform generator can be connected to a connector on the rear door of the tower to supply custom waveforms to the mode controllers. This signal can be connected to either the DC input connectors or to the AUX.IN connector. The external waveform can be used in the same manner as the internal waveform generator signals.

The procedure is as follows: 1. Unlock position calibration by pushing Function, Instron Service, Continue, Calib lock switch. 2. Push Calib Locked twice to unlock. 3. Recall Calibration by pushing Function, Instron Service, Continue, More, Position Data, Recall Data.

If the max/min displays are not stable during a fatigue test, the sensitivity may have to be reduced. The sensitivity is a function of the transducers full scale. For example, use a sensitivity setting of 0.001 with a 55 kip load cell to set the sensitivity to 55 lbs. To change the sensitivity, go to the GPIB commands and select C120,2,0.001 and then send message. (Consult your operator's manual on sending GPIB commands.)

Note: Commissioning only applies to 8500 Plus version 35 or 37, and all versions of 8800. Commissioning sets a value Ka for the stiffness of the actuator in KN/mm. This stiffness is required by the adaptive algorithm. It is one of the start-up parameters and is regarded as a system constant which is stored in non-volatile memory. Adaptive control will not work properly if Ka is incorrect.

+-0.5% of reading down to 1/250 of capacity of load cell.

T567-2001 For actuator AKX11797 T567-2002 For actuator RKX11797 T567-2003 For actuator BKX12947

Most communication errors can be solved by powering down all equipment, including machine frame, control tower and computer. They should then be powered back on in the following sequence: machine frame, control tower and computer. This should result in communication being re-established. If not, check all cables and connections and perform the restart that was described above. If this does not fix your problem, then please call Instron Tech Support at 1-800-473-7838. Please make sure that you have all relevant serial and model numbers at hand when calling.

Mobil DTE25 or equivalent.

If the crosshead clamp pressure switch is detecting low pressure in the clamps (as if they are open), then it tells the controller to use the specimen protect mode to limit the force that can be applied. For the specimen protect mode to work correctly, the load and position channel must both be calibrated and available for control. If they are not, then the power pack will be stopped instead. In most cases the position channel is always calibrated but the load channel needs to have the calibration restored or re-calibrated each time it is powered up.

If the crosshead clamp pressure switch is detecting low pressure in the clamps (as if they are open), then it tells the controller to use the specimen protect mode to limit the force that can be applied. For the specimen protect mode to work correctly, the load and position channel must both be calibrated and available for control. If they are not, then the power pack will be stopped instead. In most cases the position channel is always calibrated but the load channel needs to have the calibration restored or re-calibrated each time it is powered up.

If the crosshead clamp pressure switch is detecting low pressure in the clamps (as if they are open), then it tells the controller to use the specimen protect mode to limit the force that can be applied. For the specimen protect mode to work correctly, the load and position channel must both be calibrated and available for control. If they are not, then the power pack will be stopped instead. In most cases the position channel is always calibrated but the load channel needs to have the calibration restored or re-calibrated each time it is powered up.

The load or strain calibration channel is locked. To unlock press the following buttons on the MMI: Function System Locks Cal Lock Locked - When you push this button it will change to unlocked and you will be able to calibrate the load and the strain channels.

This problem has been fixed in Merlin V5.41 (Suite 22095). Install this or a later version to resolve this.
A workaround is shown below: When using Merlin for 8800 with a video extensometer, the gpib command c66,4,2 is not sent to the 8800 to enable the digital output special switch status. This turns on digital output 4 to clock at the data logging rate as selected in Merlin. Without this synch clock, Merlin does not store any data from any channel. Add the following entry to the Instron.ini file in the 8x00Controller section: [8x00Controller] Disable Dirty=1

You need to check the following points:

• If you are saving data during the test to a network drive, make sure no back-up software could be slowing or stopping access to the file. 
• Check that power management options (e.g. turning off the hard disk after a period of time) are switched off. 
• Make sure the screen saver is not slowing the application program down (for example, some virus scanners scan all programs on the hard disk when the screen saver comes on).

This issue has been resolved in Merlin V5.41 (Suite 22095). Install this or a later version to resolve this issue. "Rate of Load" End Test Criterion no longer misses break events. Merlin now sets up the event properly using a 100ms time window for the load drop.

Instron will make every attempt to support older generation machines. By contacting Instron Service using our Service and Technical Support Form (refer to the [question number] located at the end of each question and provide your model and serial number), we can provide you all of the current information pertinent to your system.