The Data Acquisition System Based on VXI and PCI Bus

HT-7 ASIPP

• H.Z. Wang, G. Li, J.R. LUO, Z.S. Ji, G.M. Li

• (E-mail: hzwang@ipp.ac.cn)

HT-7 ASIPP

Outline:1.Introduce the distributed data

acquisition system on HT-7 2. Hardware based on PCI/VXI

control3. Transmitting data from the bus

controller to data server 4. Cooperating with the whole

distribute data acquisition system

HT-7 ASIPP

The HT-7 data acquisition system is designed as distributed and it is mainly based on four buses:

(1) CAMAC bus (2) EISA bus (3) VXI bus (4) PCI bus.

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Chart one: basic data acquisition network structure

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PCI board hardware

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62.5/125/250/500k PCI BUS eight channels ; 12 bits 2*256KB Ram Outer clock&trigger The sampling data after A/D complete will be wr

itten to the two buffer storages by ping-pong method under the controlling of the logic control circuit.

• PCI BUS control

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We can design kernel software by let VxD to achieve IRQ in real time so as to realize the real time data acquisition in Windows operation system. VxD is a kind of binary system kernel code used to manage the Windows hardware resources in real time. We install VxD and VMM together, and them both can cooperate and share modules of system to get certain IRQ.

• PCI BUS control

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High speed （ 1MSPS) Four channels ; 12 bits VISA database （ Virtual Instrument

Software Architecture ） IEEE1394 Outer clock&trigger

• VXI BUS control

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Because the VXI equipment is to be the VPP(VXI Plug & Play) hardware layer, we need not direct visit the VXI hardware but use VISA(Virtual Instrument Software Architecture) database to achieve its control and so on. HP Corp VISA database provides VISA DLL 、 LIB document and some C program head file and those all can be direct used by Visual C++ to reduce program difficulty.

• VXI BUS control

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IEEE1394 is a serial interface standard which has a vide frequency transfer speed and it is established by IEEE standardization organization. As a computer exterior bus standard, IEEE1394 Universal connect between different equipments. has such merit:

(1)  Multimedia applied real time data transfer; (2)  Data transfer ration is 100/200/400Mbits/s; (3)  Never lose data in real time connect or

disconnect; (4)  Plug and play automatism configure; (5)  Broad band real time applied; .

• VXI BUS control

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• During the both bus(VXI/PCI) data transmitting course within the data acquisition network, we used TCP/IP Net protocol to realize the data transfer to the data servers.

• Transmitting data from the bus controller to data server

Parallel Multi-threads Work-proces

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T = n*t1+max(t2,t3)+x

t1

t1

t2t3 t2

t3t1 t2

t3

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• The shot number is the key index for us to search for certain data in the data servers,

so those data that have the same shot number will be saved together and

represents the same discharge.

• Cooperating with the whole distribute data acquisition system

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• Both PCI and VXI bus data acquisition subsystem are important for the whole distribute data acquisition system in HT-7 and improve the data precision and capacity greatly. As a kind of attempt, these work provide important scientific base for us to design the distribute data acquisition system in HT-7U.

•Conclusion

HT-7 ASIPP

THANKS