Network Based EPICS Controllers

Plan for
Network Based EPICS Driversof PLC's and Measurement Stations
Kazuro Furukawa, KEK<furukawa@kek.jp>

JHF Linac Control GroupK.Furukawa, Oct.1999.

Network Based EPICS Controllers

Plan of Control System for JHF Linac◆ Studied Control Systems at KEK
and Chose EPICS◆ During Study, Many Field Networks Found in KEK
Homemade, Proprietary, etc.
◆ However at KEK e– Linac,
Many TCP/IP Connected Controllers (>150)
No new Field Networks Recently

K.Furukawa, Oct.1999.

Network Based EPICS Controllers

Network Connected Controllers◆ Simplified Software, Management, TroubleshootingEfficient in Speed, Cost, Manageability
Do not Consume Human Resource much
◆ Selection of Standard Network Device Technology
Standard Software
Flexible in Designing the Network
Easily Understood (the Same Technology at Oficces)◆ Normally UDP/IP for Simplicity and Error Handling
TCP/IP as well (cf. out-of-band TCP packets)

K.Furukawa, Oct.1999.

Network Based EPICS Controllers

Programmable Logic Controller; PLC◆ Modern PLC's are Powerful and Flexible
Good Candidate for Remote I/O Controllers◆ Not too Fast on the Network (5 to 30 millisecond Response)
but Fast Enough for General Purposes◆ Pre-processing of Control Variables
Scientific Functions, Floating Point Calculations◆ Chose Yokogawa's FA-M3 (Factory ACE)
Maintenance Capability over Ethernet/TCPIP
Not from other Venders in Japan◆ At JHF,
Vacuum, Magnet, Ion Sourceand Microwave Equipment
K.Furukawa, Oct.1999.

Network Based EPICS Controllers

Measurement Station◆ Waveform Observation
GPIB connected Oscilloscopes or VXI◆ At JHF,
Beam Pulse of Several Hundred Nanosecond
Cost Performance
Noises from Modulators◆ Chose Yokogawa's WE7000 (as well as VXI)◆ Network Specification was Disclosed
Evaluating IP Communication Software on Unix(Originally Developed for Windows Environment)

K.Furukawa, Oct.1999.

Network Based EPICS Controllers

K.Furukawa, Oct.1999.

Network Based EPICS Controllers

PL C m anagem ent
O P I 's
C A c lie n ts
s ta tio n s

C A access

N e tw o rk
M a in te n a n c
S w itc h (s )P o llin g ,P L C 's
IO Ce tc
( V M E o r P C( )N e t w o r k C o n t r o l l

K.Furukawa, Oct.1999.

Network Based EPICS Controllers

EPICS Software◆ IP Software is Available Standard on VxWorks◆ Synchronous Access is Straightforward◆ But Response Time of 5 - 30 Milliseconds
EPICS do not Allow This
◆ Asynchronous Version should be Developed◆ First, Test Implementation on Unix
Then, to VxWorks

K.Furukawa, Oct.1999.

Network Based EPICS Controllers

Software for PLC◆ PLC Access Routine at e– Linac was Generalized
Tested on Unix
◆ Synchronous Version of EPICS Device Support
Help Understanding this Architecture◆ Testing Several Access Method◆ On-demand (Interrupt) Protocol
Host IP Address Have to be Hard-coded◆ Block of PLC Memory as Shared Memory
Between IOC and PLC◆ Naming Scheme for OUT/INPK.Furukawa, Oct.1999.

Network Based EPICS Controllers

Software for WE7000◆ Software is Evaluated and Investigated on Unix
◆ Status of a Station Have to be Managed on HostImplemented with Threads◆ Port Software on to VxWork IOC
Replacing POSIX Thread with VxWorks Tasks◆ Waveform Record will be Implemented FirstK.Furukawa, Oct.1999.

Network Based EPICS Controllers

Conclusion◆ IP Network Based Controllers
Such as PLC or WE7000
Simplify Designing Control System(While Keep Studying Other Field Networks)◆ Software is under Implementation
Straightforward and Will be Realized soon
◆ More Investigation on Naming SchemeSpecification of Variables◆ Hardware/Software will be Installed
From the Beginnig of the Next Year
K.Furukawa, Oct.1999.

Network Based EPICS Controllers

K.Furukawa, Oct.1999.