VEPP-4 Control System Upgrade
A.Aleshaev, S.Karnaev, B.Levichev, I.Protopopov, S.Tararyshkin
Budker Institute of Nuclear Physics (BINP)
Lavrentjeva 11, Novosibirsk, 630090, Russia
Abstract
VEPP-4 control system requires an upgrade to support
the system functions. The existing control system is basedon CAMAC embedded 24-bit computers. An upgrade
would allow us to use PC-based application programming.
In the paper we will describe an approach which allows
us to integrate the existing control system as a real-timeprocess level into a three-layer architecture which resembles the standard model (Fig.1)’:•PCs on an operator level,•
existing computers on the process level,•
microprocessor-based front-end electronics on theequipment level.
We are to use a data flow server to link the operator andprocess levels, to fit net protocols and data format, and toreduce a number of connections between the levels. This
server includes dynamic database with values of all control
and measurement data. Both networks between the levels
are based on Ethernet.
The access from the operator level to the process level isprovided by home developed applications. The operator
level network is private and separated from the BINP
public network by a bridge.
1 Introduction
VEPP-4 facility was commissioned in the end of 1970’ s
as a facility for providing experiments with colliding
electron-positron beams. The first version of VEPP-4
control system was based on ODRA-1300 24-bit
computers (analogous to ICL-1900 series). In the early
1980’ a necessity for the control system upgrade became
obvious for the following:•existing electronics became obsolete, but a full rangeof custom-made CAMAC electronics for automation(different types of DACs, ADCs, multiplexers,
switches, etc) was developed in BINP,•in 1983-1985 an autonomous crate controller
emulating instructions set of ODRA-1300 wasdesigned,•
existing ODRA-1300 computers became obsoleteand unsupported.
This upgrade was completed in the end of 1980’ s.
Now the control system has a star architecture ofIntelligent Crate Controllers (ICCs) with a central nodesupporting a boot of peripheral computers, intercomputercommunications and file server functions. A set of Passive
CAMAC Crates (PCCs) with front-end electronics is2 Upgrade requirements

Possibilities of the existing control system have become
non adequate for a great number of control needs,
especially for feedbacks and graphics. The upgrading of
VEPP-4 control system would be done in two stages. We
split the upgrade in to two stages because a long period oftime is needed to develop new application programs for theoperator level of a new system.
The goals of the first stage of the upgrade are:•to replace a large number of interface types forintercomputer communications with one custommade
CAMAC-embedded
Ethernet-CAMAC
adapter,•to eliminate obsolete system modules and devices
that are not manufactured or soon will be,•to eliminate home developed file system on existing
hard disks (total 40 Mbytes) by PC file system; atthe first stage of upgrading this PC provides
functions of the existing central node (network
connections, a file server and a bootable computer).
The main requirement for the first stage of the upgrade isto preserve the developed application software.
At the second stage of the upgrade PCs will be used asoperators and graphical consoles. At the second stage, thecentral PC becomes DataBase and Transmit Server(DBTS) and additionally provides the next functions:fitting of net protocols and data format, reducing data flow
between the operator level and the process level, providing
dynamic database and proxy server functions.
Fig.1 shows a simplified scheme of new VEPP-4 controlsystem.
3 The first stage of upgrade developments
The next developments are included into the first stage ofthe VEPP-4 control system upgrade:•Virtual Terminal Process (VTP) in existing ICCs andPCs, such a process which provides in PCs a virtual
terminal for running applications in ICCs,•
Ethernet-CAMAC Adapter (ECA): 2M CAMACmodule includes commercial Ethernet-for-PC board
and firmware realized packet driver,•multiprocess server on PC under MS DOS; now it
has a full acceptable performance
forfileaccessesconnected in a star configuration via serial
data links toeach ICC [1].
and intercomputer communications about 100 - 200
Kbytes/s.
As all new system implementations are additional toexisting system software, the change of interfaces will notaffect the existing applications

PCPC

Ethernet LANBINP

EthernetPCACEACE.

Figure 1 Scheme of the VEPP-4 control system upgrade4 DataBase and Transmit Server4.1 Dynamic DataBase
Dynamic DataBase (DDB) is arranged in memory ofDBTS and includes:•values of all control and measurement channels (coilcurrents, voltages, temperature, vacuum, etc.),•beams parameters ( values of beams currents,•status information (polarity (electrons or positrons)
and readiness of the systems, particles energy, etc.)
The ICCs run local programs that periodically read andcontrol modules on their local CAMAC serial highways.
For example, all the data in ICCs controlling pulsed
systems are updated at a 1 Hz rate. The ICCs only senddata packet through the network to DDB for the parametersthat have changed. Operator level program sends control
packet through DBTS to ICC to perform control ormeasuring act. After the act has been performed, ICC
returns new data to DDB and sends the answer to the initial
operator program.
4.2 Types of Interchanging Data Packets
The next types of interchanging data packets are allowedfor DBTS:•
between the operator level and the process level
without modification,•
between the operator level and the process level withdata format modification (24-bit word ⇔ 32-bitword),•between DBTS and ICC,••

between DBTS and an operator application,from one ICC to another.

4.3 Static DataBase
A Static DataBase (SDB) is arranged on DBTS disk andconsists of three parts. The first part of SDB includes a fulldescription of the control electronics configuration:
addresses of crates, types and positions of modules, etc.
The second part includes the description of control
channels: records of text, integer and real variables. The
third part of SDB includes files, which are sets of operating
data values for different parts of the facility.
5 Conclusion
The first stage of the control system upgrade would becompleted by the end of the summer next year. Now wehave developed most of the system implementations (VTP,software for the PC-server) and have completed a design ofECA. Hereafter a realization of the first stage will allow us
to extend a function range of the server and to integrate
operator level applications while keeping the operated
control system available. It is important for us to make thesecond stage at the same time, when VEPP-4 facility runs
into operation.
6 References[1]

A.Aleshaev,
et.al. VEPP-4 Control System,ICALEPCS'95, Chicago, USA, p.799, F-PO-2.