The Control System for Magnet Power supplies (MPS) of Indus-2 is one of the systems that is used to set up the dynamics of the beam in the accelerator. This system monitors and controls nearly 200 MPS. The control system facilitates setting up different MPS for beam injection, ramping and storage. The beam dynamics pose different requirements for all these phases. The flexibility to operate power supplies in different modes and providing for the stringent accuracy and stability requirements is the hallmark of the system. The best accuracy and stability of the references maintained at the supplies inputs is 15 ppm which is assured by the hardware. The system facilitates key functions like magnet cycling and synchronous energy ramping. The system also makes available useful diagnostics information for the operators and system experts. The ramping function also caters to the ramping of RF cavity gap voltage synchronously with the power supply currents. Indus-2 MPSCS system has 40 Equipment Controllers connected to 1 Supervisory Controllers.

Features and functionality of the MPSCS:
MPSCS is an interface between the operator and the MPS. It brings the status and controls of various parameters of all the power supplies in a centralized control room. The functions and services offered by MPSCS are- Status Monitoring: It provides digital statuses information of various MPS parameters viz. Local/Remote mode, Auxiliary ON/OFF, Load PS ON/OFF, Ready, AC Good , Load Temperature etc..

Readback: It provides analog readback of MPS currents and reference signals with an accuracy & resolutions of true 16 bits for high accuracy PSs (50 ppm) and accuracy & resolutions of true 14 bits for low accuracy PSs (500ppm & 1000 ppm)

Controls: It provides digital control commands for Load Power ON/OFF, Aux. Power ON/OFF & Reset.

Analog Reference: It provides programmable stable reference (0 to 10 V & -10 V to +10 V) with an accuracy and resolution of true 16 bits with 15 ppm stability for high accuracy PSs (50 ppm) and accuracy and resolution of true 14 bits with 60 ppm stability for low accuracy PSs (500ppm & 1000 ppm).

Configuration: It facilitates the configuration of various PSs parameters viz. Default slope, minimum & maximum operating value, range etc.

Cycling: Cycling the output current of Magnet Power Supplies (MPS) is required for repeatable and history-free magnetic field profile required for proper & repeatable operation of Indus-2 machine. MPSCS facilitates the cycling of 138 PSs, various cycling parameters viz. Slope, minimum value, maximum value , hold time etc. can be configured for individual PSs participating in the cycling process.

Ramping: The injected beam of 550 MeV from Booster Synchrotron is ramped up to 2.5 GeV in Indus-2 storage ring. This ramping operation requires synchronous current ramping of magnet power supplies along with cavity gap voltage ramping of all RF cavities. Control system provides programmable ramp profile generation with flexibility as per requirement of beam dynamics. Synchronisation of all devices participating in the ramping process is mainly governed by way of centralized ramp clock generation and distribution.

Repeat Ramping: It facilitates repeating the last successful Ramp operation without the need of carrying out the Ramp Data calculation again. All PS and RF cavities used in last Ramp operation are ramped with the use of the data calculated in the previous successful ramping operation, it is quick and avoids calculation steps.

Synchronous Data Capturing: It captures control reference and MPS readback signals simultaneously and synchronously for all the power supplies undergoing Ramping. This is done using the ramp-clock itself that makes the process synchronized at distributed VME stations and helps in analyzing any deviation/transient during ramping process.

Displaying and recording of Debug information: It provides the monitoring and recording of various diagnostic parameters viz. Readback of reference signals, ADC,DAC oven temperatures, ADC/DAC board status, CPU status etc.
Facilitates synchronous setting of the PSs: It facilitates synchronous settings of PSs by using the broadcast command features in PROFI communication.This feature is advantageous in cycling, SOFB,tune feedback correction, group setting etc.

Controlled switching of magnet power supplies :Power supplies needs to be switched softly. During switching ON and OFF of power supplies it is to be ensure that the reference signal should be at minimum value. The power supplies are switched ON and OFF through control system by different mechanism viz. during file loading, shutdown all power supplies command and issuing ON/OFF command for individual power supplies by the user the control system software ensure the controlled switching of power supplies. The software takes care of bringing the reference signals to its minimum value in a controlled manner before switching it ON or OFF. It does it through the controlled and programmable rate of rise of reference signal generation in the DAC board hardware.