DESCRIPTION

The Newport (formerly Klinger) MM2000 and MM3000 motor controllers are supported by spec on both RS-232C and GPIB interfaces. The MM2000 is also supported on the ISA bus interface. On the serial interface, spec supports the daisy chaining available on the MM2000 and MM3000 controllers. All these controllers can be used both with DC motors (with encoders) and with the 1.5M-type stepper motors.

The controller is selected in the config file as

RS_MM2000 = device_name baud_rate number_of_motors

RS2_MM2000 = device_name baud_rate number_of_motors

GP_MM2000 = gpib_address number_of_motors

PC_MM2000 = base_address number_of_motors

depending on the interface being used. The second example above selects the daisy-chained RS-232C configuration.

When running the configuration editor, switch to the device configuration screen to select the appropriate interface. On the motor screen, select the MM2000 or MM2000_E controller type for each motor to be controlled. The latter choice indicates encoders are being used.

By default, motors are automatically assigned to the controller channels in the same order they appear on the motor screen. If there is more than one controller, the channels are assigned to the controllers in the order in which the controllers appear on the motor device screen. Also available is the new nonconsecutive channel assignment feature that has been implemented for selected motor controllers. Controller unit and motor channel numbers can be selected and assigned on the second line of the motor configuration screen in any order. Not all channels need to be assigned.

When using the daisy chain feature, if automatic channel numbering is selected in the configuration file, the controller daisy-chain addresses must be assigned consecutively starting with address 0 using either the controller dip switch, the controller front panel menu or by sending a command over the serial interface. If the unit/channel configuration is used, the daisy-chain addresses will be derived from the channel number.

PARAMETERS

spec allows a number of additional parameters to be set in the configuration file and by the motor_par() function for these controllers. Use the configuration editor to establish the long-term values of the parameters in the configuration file. Use motor_par() to make changes to the parameters that only are in effect during a particular spec session. To set the parameters from the configuration editor, use the m command from the main motor screen to access the optional-parameter screens.

The following parameters are associated with DC motor operation. The two-letter command sent to the motor controller associated with each parameter is given in parenthesis.

motor_par(motor, "dc_proportional_gain" [, value])

If value is given, sets the proportional gain, otherwise returns the current value. ("KP")

motor_par(motor, "dc_derivative_gain" [, value])

If value is given, sets the derivative gain (or damping constant), otherwise returns the current value. ("KD")

motor_par(motor, "dc_integral_gain" [, value])

If value is given, sets the integral gain, otherwise returns the current value. ("KI")

motor_par(motor, "dc_integration_limit" [, value])

If value is given, sets the integrator limit, otherwise returns the current value. ("IL")

motor_par(motor, "dc_sampling_interval" [, value])

If value is given, sets the derivative sampling interval, otherwise returns the current value. ("DS")

motor_par(motor, "dc_following_error" [, value])

If value is given, sets the following-error threshold, otherwise returns the current value. ("FE")

To set the gain for the tth motor, for example, use

motor_par(tth, "dc_proportional_gain", 1000)

The function

motor_par(tth, "dc_proportional_gain")

returns the current value of the "dc_proportional_gain" parameter.

Another motor_par() parameter is:

motor_par(motor, "slop" [, value])

If value is given, sets a threshold value in steps, below which spec suppresses position discrepancy messages when spec and the motor controller disagree about motor position, otherwise returns the current value.

COMMAND PASS THROUGH

Command pass through is available using the following:

motor_par(motor, "send", cmd)

Sends the string cmd to the MM2000 channel associated with motor. For example, set cmd to "SB1,3,8" to set output bits 1, 3 and 8.

motor_par(motor, "read", cmd)

Sends the string cmd to the MM2000 channel associated with motor, as above, and returns a string containing the response.

JOYSTICK

To enable joystick control for a particular motor, use the command

motor_par(motor, "joy_on", channel)

where motor is the motor number and channel is the channel number, as explained in the Klinger manual for the JY command. To disable joystick control, use the command

motor_par(motor, "joy_off")

Not only does the "joy_on" command send the proper joystick enable codes to the MM2000/MM3000, but it also changes behavior within spec. In particular, position discrepancies between spec and the controller are automatically corrected in favor of the controller for all commands, except for the sync and reconfig commands. (A message is printed, though, when the position correction is made.) In addition, when joystick control is enabled, the motor controller is queried to read the current position for the motor on all getangles commands, not just when the motor is active, as is the joystick-disabled case.

Suggested macros for controlling the joystick are:

def joy_on '
    if ($# != 2) {
            print "Usage:  joy_on motor channel"
            exit
    }
    _check0 "$1"
    motor_par($1,"joy_on",$2)
'

def joy_off '
    if ($# != 1) {
            print "Usage:  joy_off motor"
            exit
    }
    _check0 "$1"
    motor_par($1,"joy_off")
'

To make things even easier, you could define macros such as

def on_joy '
    joy_on tth 1
    joy_on th  2
    joy_on chi 3
    joy_off phi 4
'

and

def off_joy '
    joy_off tth
    joy_off th
    joy_off chi
    joy_off phi
'

LIMITATIONS

The MM2000/MM3000 motor controller only allows its internal position registers to be set to zero. Thus the chg_dial() function (used by the set_dial macro) will not accept nonzero position arguments. Similarly, if there is a motor position discrepancy between spec and the controller, if you choose to change the controller register position to agree with spec and if the spec dial position is not zero, the spec dial position will instead be changed to agree with the controller, and the the spec offset parameter will be changed to keep the same spec user-units position.

VERSION

The above description describes the MM3000 firmware version 2.3.