LabVIEW drivers - MKS Pressure Controller

MKS Pressure Controller

The MKS 600 Series Pressure Controller (651 unit) comes with an extensive manual describing the serial communication protocol. The driver is presented as a LabVIEW API which implements all public functions and in which all VIs have a uniform connector pane.

Driver installation

Create a directory _mks in the user.lib directory of LabVIEW e.g. C:\Program Files\National Instruments\LabVIEW 7.1\user.lib\_mks and unpack all files from _mks.zip in this new directory. This should add a new menu to the User Libraries of the Functions Palette:

(In LabVIEW 2011 SP1 use 'Tools>>Advanced>>Edit Palette Set' to add the MKS subpalette to the User Libraries with 'Insert>>Subpalette...>>Link to a directory'.)

The Functions Palette contains 4 sub-menus:

• Commands
  
  The API contains a VI for each (write) command. Where possible similar commands are comprised into a single VI which requires an additional selection input parameter.
   
  
• Requests
  
  The API contains a VI for each (read) request. Where possible similar requests are comprised into a single VI which requires an additional selection input parameter.
   
  
• Testfiles
  
  There are 3 testfiles e.g. to test the functionality or to obtain an overview of all functions. See Test Programs for more information
   
  
• Polymorphic requests
  
  The request VIs that require an additional selection input are also presented as polymorphic VIs.

Furthermore the Functions Palette contains 2 VIs to open and close the serial connection.

Test Programs

From the menu select one of the following:

• mks trial.vi
  This program reads all known parameters. In case of similar parameters it displays the value for "setpoint A".
• mks trial set values.vi
  This program reads all parameters that can be changed. (In case of similar parameters it displays the value for "setpoint A".) After that, it allows to change the parameters. WARNING: There is no range check for numeric values etc..
• mks tree.vi
  This program doesn't work as such but it allows to easily recompile all sub-VIs.

Remarks

• The Pressure Controller doesn't send a verification signal after some (write) command has been issued. The manual describes a method to overcome this issue: After changing a parameter issue a (read) request to read back the affected parameter. By default the VIs will use this method.
• The command "L" (Learn) can not be stopped with "Q" (Quit) as stated in the manual. The Controller will leave the learning mode after some 30 seconds. The API doesn't contain a quit learning function.
• The calibration function will generate an error message on the Pressure Controller which has to be manually reset.
• The VIs have been made with LabVIEW 7.1. Professional Development System.

Downloads

_mks.zip