High voltage control software

A high voltage control software for FINUDA straw tubes. S. Sarwar and N.Qaiser 6-02-1998 This document describes a collection of programs written in LabVIEW to control/monitor CAEN high voltage power supply by a personal computer. The computer should be equiped with a HS CAENET PC controller interface and a network card. The software allows the user to interactively control or monitor high voltage channels and also permit to do the same via network by a remote machine. Therefore the software, for its full potential capability, requires an mSQL server runnig at a remote UNIX host with an HV data base table. However programs for manual control and monitoring are also provided in case a server or network is not available.

Hardware setup

Following diagram shows the hardware setup for the HV control system.

Hardware requirments IBM PC or compatible:

Running LabVIEW 4.0 Under Windows 95

HS CAENET PC Controller Card Model A303 from CAEN inserted in an XT/AT Slot

Base IO address = x310

TCP/IP network interface card

HV Supply:

Model SY 527 or other supplies with HS CAENET interface.

Software structure

The structure of the software can be divided into three main parts.

a. User interface plus flow control.
b. TCP/IP node.
c. HV node.

Part (a) controls the flow of data among a user, an mSQL server and HV supply. Part (b) takes care of the communication over TCP/IP network and Part (c) realizes the interfaces to HV supply through HS CAENET line. Following capabilities have been built into the control software structure.

Setting of HV parameters

Setting of HV supply parameters is possible through two instrumentes: Netset and Manset.

NetSet

This instruments provide user friendly channel adressing and builds a target list of selected channels. Channels in the target list can be added in the follwoing ways:

hardware adressing by specifying crate,board and spigot numbers,
physical location in the detector by specifying layer number,
channel name (from mSQL dbase) adressing,
select function of mSQL with all its matching features.

All HV supply parameters like Vset, I0, Trip, Rampup etc, corresponding to the channels added in the target list, are loaded from the mSQL high voltage table and displayed on the screen for user verification and modification in some cases. Once verified and selected the power ON/OFF operation, these parametres are passed onto SY527 carte.

ManSet

This instrument is meant for manual setting of HV parametres in case of non availability of network link to the mSQL database. Channels can be specified by their hardware adress and HV supply parameters have to be eneterd manually.

Monitoring and display of HV status

Monitor instruments provide a flexible, user friendly, fully configureable enviorenment for display of HV status. This includes HV parameters like channel voltage/current, and reporting of channels with their voltage out of tollerance and cahnnels in over current or in trip state. As for the setting operation, two instruments NetMon and ManMon are provided to work both in a networked environment with an mSQL databse or without it. Adressing and building target channel list is similar to that of setting instruments.

NetMon

Remote operations

A TCP server has been incorporated in the HV control software which receives ASCII commands
from the network and sends ASCII response and status data. This feature provides a TCP interface to SY527 supply and permits the following remote operations:

control and monitoring of HV from code running on different plateforms and machines.
HV status communication to FINUDA DAQ program.
setting of HV parameters in slave mode for single count rate plateau routines.

Logging

The control and monitoring instruments, NetSet and NetMon, keep a comprehensive Log of HV information. It includes:

record of all HV parameters upon each setting operation
periodic logging of monitored HV status along with channels with error.

HV killing

In case of a kill signal, which can be generated by setting a labview global variable, all HV channels are "killed". This safety feature permits an immediate HV killing in case of an emergency situation detected by gas control system.