Welcome | spec | C-PLOT | Support | Users | Contact
 



Motors
Counters
MCA
Interfaces
    Hardware reference : Motors : Missouri University Research Reactor Motor Controller

Missouri University Research Reactor Motor Controller



Interface:
  • GPIB


config file

HW_MURR = number_of_motors 

edconf:   DEVICES screen 
MOTORS        DEVICE   ADDR  <>MODE  NUM                             <>TYPE 
   YES                                13   Missouri Research Reactor Motors

edconf:   MOTORS screen 
Number: <>Controller     0:  MURR_E   1:  MURR_E   2:    MURR   3:    MURR 
Unit/Channel                    0/1          0/2          0/3          0/4 
Name                      Two Theta        Theta          Chi          Phi 
Mnemonic                        tth           th          chi          phi
The University of Missouri Research Reactor uses custom motor controllers. Each channel of the motor controller requires one GPIB address. The GPIB address is set using the channel number in the required unit/channel configuration on the motor screen of the configuration editor. The unit number is not relevant for these motors.

The controller type MURR_E or MURR is selected depending on whether or not the controller channel uses an encoder.

There are several unique parameters associated with each motor channel. The parameters assume default values when the controllers are powered up. Alternate values can be set in the config file that will be programmed by spec . The values are:

Name Parameter Name Power-On Value
Modulo Generic Parameter 1 360000
Grain Generic Parameter 2 5
Direction Generic Parameter 3 1
Drive Mode Generic Parameter 4 1
Cut Point Generic Parameter 1 0
For the modulo parameter, the value 360000 is appropriate for rotation stages. For translation stages, the maximum value (999999?) would be appropriate. The grain parameter is a multiplier for the steps sent to the motor by spec and should be simply related to a gear reducer value. The direction parameter should be set to zero to reverse the direction of the motor so that its position agrees with the controller display. The drive-mode parameter changes the meaning of the output signals. For a value of one, the output signals are count-up/count-down. For a value of zero, the output signals are step/direction.

The cut-point parameter allows negative positions to be reported by spec , even though the controller only reports positive positions. Positions reported by spec will be between the cut point and the cut point plus the modulo parameter multiplied by the step size parameter. For a module of 360000 and a cut point of -180, positions will be between -180 and +180, for example.

Top