DESCRIPTION

The NT-2400 from Laboratory Equipment Corporation is an ethernet-based instrument providing motor control, timer/counter functions and MCA capability.

Note, as there is a 20-character limit to the device names entered using spec's hardware configuration editor, it will be helpful to have a short name in the /etc/hosts file to identify the NT-2400 host, such as

192.42.172.13   nt2400.localnet.edu nt2400

To configure spec for the NT-2400 hardware, either run the config macro from spec or the configuration editor edconf directly. Change to the Devices screen to configure the hostname and port number of the motor controllers and counter/timers. The selections will look something like the following, with the NUM field specifying the total number of motors/counters at the specified host. (Note, type the single quote ' to begin string-entry mode to enter the DEVICE name. Use the < and > characters to select from the TYPE menu.)

Motor and Counter Device Configuration (Not CAMAC)

 MOTORS      DEVICE ADDR <>MODE NUM                           <>TYPE
    YES nt2400:6051               6         Labo NT-2400 Motor (UDP)

SCALERS      DEVICE ADDR <>MODE NUM                           <>TYPE
    YES nt2400:6051               8 Labo NT-2400 Counter/Timer (UDP)
    YES nt2400:6051               8      Labo NT-2400 Counters (UDP)

For the scaler configuration, the first example is for when one of the scaler channels is to be used as master timer. With the second example, all the scalers are used only as counters.

The MCA devices are configured on the Acquisition-type device screen of the configuration editor. For two MCA modules on the same NT-2400 host, the screen would look something like:

MCA (1D) and Image (2D) Acquisition Device Configuration

MCA          DEVICE ADDR <>MODE                               <>TYPE
 0  YES nt2400:6051                           Labo NT-2400 MCA (UDP)
 1  YES nt2400:6051                           Labo NT-2400 MCA (UDP)

Configure individual motor channels on the Motor screen. Select the NT2400 controller type for each motor channel.

Number: <>Controller  0:  NT2400  1:  NT2400  2:  NT2400  3:  NT2400
Unit/Channel                 0/1         0/2         0/3         0/4
Name                   Two Theta       Theta         Chi         Phi
Mnemonic                     tth          th         chi         phi

Unit numbers are assigned in the order in which the NT-2400 motor controller units are specified on the Devices screen, and start at zero. Channel numbers start at one to match the NT-2400 numbering convention. It is not necessary for the motors to be consecutively ordered in the configuration.

The pulse-mode parameter (100 or 200) can optionally be entered on the second optional motor parameter screen (accessed by typing m twice from the main motor screen). Enter values for the pulse mode in the field for Generic parameter 1. If no value is entered, the default value of 100 is used. In addition, the limit and home switch polarity can be optionally configured by entering a value for Generic parameter 2. The coding for switch polarities is as follows:

Bit 0 set: ccw limit positive

Bit 1 set: home switch positive

Bit 2 set: cw limit positive

Configure the NT-2400 scaler channels on the Scaler screen to look something like the following:

Scaler (Counter) Configuration

Number      Name  Mnemonic  <>Device  Unit  Chan   <>Use As  Scale
     0   Seconds       sec    NT2400     0     2   timebase   1000
     1   Monitor       mon    NT2400     0     1    monitor      1
     2  Detector       det    NT2400     0     3    counter      1

For the NT-2400, only channel 2 can be used as the time base channel and only channel 1 can be used for the monitor preset counter. If there is no monitor-type preset counter, and there are only two counter channels, then channel 1 should be configured as the ordinary counter detector channel.

With such a configuration, all the standard commands for moving motors, counting and accessing the MCA are available.

Note, setting spec's debug level to 128 (using the debug macro or by assigning a value to the DEBUG built-in variable) will have spec display the commands sent and data returned from the NT-2400 in a semi-readable form.