Lakeshore Learning Materials 622 - Manual (Page 69)

Lake Shore Model 620/622/623/647 Magnet Power Supply User’s Manual
Options & Accessories 6-1
CHAPTER 6
OPTIONS AND ACCESSORIES
6.0 GENERAL
This chapter covers MPS options and accessories: Model 6224 IEEE-488/Serial Interface installation
(Paragraph 6.1), Model 6226/6476 Liquid Helium Level and Gaussmeter Input Card (Paragraph 6.2), Model
6228 Persistent Switch Heater Output (Paragraph 6.3), Model 6228-2 Persistent Switch Heater Output
(Paragraph 6.4), and Accessories (Paragraph 6.5).
6.1 MODEL 6224 IEEE-488/SERIAL INTERFACE
This option interfaces with a Customer-supplied computer equipped with a compatible IEEE-488 or Serial
Interface. It accesses operating data and stored parameters and remotely controls front panel operations.
Only one Model 6224 is required for multiple MPS installations. See Chapter 4 for MPS remote operation.
Installation Procedure
WARNING
• This procedure is intended for trained service personnel who understand electronic circuitry and
the hazards involved. Do not attempt this procedure unless qualified.
• To prevent shock hazard, turn off the instrument and disconnect AC line power and all test
equipment before proceeding.
1. Turn unit OFF and disconnect power cord.
2. Remove the two screws of the blank option cover plate to the far left of the MPS rear panel and remove
the cover plate. If another option exists in this slot, remove it. The IEEE cable should point down. Install
the option in the far slot to avoid IEEE cable interference with the power cord.
3. Slide the Model 6224 board into the MPS with the board handle towards the bottom of the MPS. Tighten
the two screws that secure the board to the MPS rear panel.
4. (If Required) Install the option removed from the Model 6224 slot into a different slot.
5. Set the IEEE-488 operating parameters as outlined in Paragraph 4.1.1 and the Serial Interface as outlined
in Paragraph 4.2.2.
6.2 MODEL 6226/6476 LIQUID HELIUM LEVEL AND GAUSSMETER INPUT CARD
The Model 6226/6476 Liquid Helium Level and Gaussmeter Input Option combines liquid helium level and
field monitoring in one input card. It monitors liquid level in percent, inches, or centimeters, and field in
kilogauss or tesla. The field measurement is quantitative. Each input has independent excitation.
The level probe interfacing supports NbTi superconducting filaments and includes entry of probe length and
determination of probe resistance over the length. A unique level probe zero reference feature allows the user
to define the current liquid level reading as the “zero reference” and reads levels above or below that
reference. A software level alarm notifies the user when the continuously variable liquid level set point has
been reached.
When the liquid level measurement is not active, the field measurement is. The field interfacing supports Hall
sensors and includes probe zero and entry of probe sensitivity in millivolts per kilogauss.
The Model 6226 and Model 6476 have the same level circuitry. The Model 6226 Gaussmeter is designed to
operate with Hall sensors requiring 100 mA of excitation current. The Model 6476 Gaussmeter is designed to
operate with high sensitivity Hall sensors requiring 1 mA or excitation current. Cards identified by a 1996
copyright containing 6XX6.S firmware are field-configurable to either model.