Question:
What reading material will help me understand VXI?
Answer:
In order to fully understand VXI you need to understand both the
hardware and the commonly encountered commands for controlling it. Here is
my suggested list of reading material and my comments about who should have
them.
==================== Understanding VXI Hardware ===========================
The first thing to read is: Feeling Comfortable with VXI bus,
P/N 5952-3080 from Hewlett Packard. This gives some history and introduces
you to VXI.
If you are a casual user, the next thing to do is to buy hardware and
read those manuals.
If you wish to understand in detail how everything really works then
you must read the specs. They are very detailed and complete.
If you are using a B-size VXI system over HP-IB there is little true
need to understand all of the internal workings of VXI. If on the other
hand you are using a C-size system with a embedded computer doing high
speed programming over the backplane or you are designing a module then you
should be familiar with both the VME and VXI spec.
VXI hardware started with the VME bus spec:
ANSI/IEEE STD1014-1987
VMEbus International Trade Association
10299 N. Scottsdale Rd., Suite E
Scottsdale, AZ 85253 USA
The VMEbus spec describes the backplane signals in detail this includes:
Data Bus--- 8,16,32 bit capabilities & timing
Arbitration Bus--How multiple CPUs can use one backplane
Priority Interrupt Bus--How backplane interrupts work
Utility Bus--SYSCLK,SERCLK,SERDAT,ACFAIL,SYSRESET,SYSFAIL
The VXI bus System Specification: HP P/N E1400-90006 includes nine major
parts that are VXI-0 thru VXI-9
VXI-0---Printing history & short description of each part
VXI-1---Provides the origninal additions to the VME spec
Module sizes-- A,B,C,D
P1 connector = same as VME
P2 connector = middle row same as VME provides 32 bit
outer rows dfines CLK10, MODID lines
TTL & ECL triggers, SUMBUS, LOCAL BUS, RSV2-3
P3 connector = defines CLK100, SYNC100, STARX, STARY, ECLTRG2-5
LBUS12-35, RSV4-7
MODULE & MAINFRAME--Shielding, cooling, power, keying, environmental
EMC--Conducted & Radiated Emisions & Susectibility EMC test methods
Device operation--register locations & definitions,
message, register, & memory devices
commander / servant rules
interrupts, communication protocals
resource manager, initialization, self-test
Device implementations--mapping IEEE 488.2 to the backplane
Command & event formats--word serial commands
Dynamic configuration--optional alternative to logical
addresses on switches
VXI-2--Extended Register based devices and Extended Memory devices
VXI-3--Word Serial Commands for Version and Serial Number Identification
VXI-4--Common Mnemonics
VXI-5--Common ASCII System Commands
VXI-6--Mainframe Extender
VXI-7--Shared Memory Data Formats
VXI-9--Shared Memory Communication Protocal
Once you have read the VME and VXI specs. then the following are good
reading from Hewlett Packard. These describe the steps you that you will go
thru in creating a C-size VXI system with a Command Module. Many aspects
of the spec will be clarified by reading these:
C-Size VXIbus Systems Installation and Getting Started Guide.
P/N E1406-90020
Command Module HP E1406A Users Manual P/N E1406-90001
Supplemental reading from Hewlett Packard that will provide further
insights into the history and initial development of VXI include:
VXIbus Compendium of Papers---literature number 5954-9686
Hewlett-Packard Journal, April 1992
The best source of current VXI news is the VXI bus Newsletter it
covers all manufacturers and all industry wide developments. All system
developers should subscribe to this.
Bode Enterprises
8380 Hercules Drive, Suite P3
La Mesa, CA 91942
Phone: 619-697-8790
================ Understanding the HP-IB Interface ======================
A common way to connect to connect to a VXI system is with a HP-IB
bus. Here is some suggested reading to understand it.
I would recommend that everyone should have a copy of the Tutorial
Description of the Hewlett-Packard Interface bus and only those who enjoy
spec reading or who are designing a module should get the 488 and 488.2
specs.
Tutorial Description of the Hewlett-Packard Interface bus
from: Hewlett Packard, P/N 5952-0156
Describes the technical fundamentals of the Hewlett-Packard Interface
Bus. This document is the easiest to read source on IEEE 488.2 Common
Commands. Recommended to first time programmers.
The following two standards are available from:
Institute of Electrical and Electronic Engineers.
345 East 47th Street
New York, NY 10017 USA
IEEE Standard 488-1978
This describes the technical fundamentals of HP-IB operation.
IEEE Standard 488.2-1987
This describes the underlying formats and and data types used in SCPI
and defines Common Commands.
========= Standard Commands for Programmable Iinstrumentation =========
The first thing to do is to get a over all understanding of how
commands are structured. I recommend that every one read:
A Beginners Guide to SCPI
by Barry Eppler
HP Part #5010-7166
Addison-Wesley Publishing Company
One Jacob Way
Reading, Massachusetts 01867
Phone: 1-800-333-0088
or 416-447-5101
All HP based VXI understands SCPI. Each instruments manual will
describe which SCPI commands that instrument understands. In almost all
cases reading the instruments manual is the best way to understand how it
works. Instruments will implement standard SCPI commands plus it is likely
that they will have a few non-standard commands.
The full standard is good to have if you anticipate getting a wide
range of instruments and want a idea of what command structure to expect.
The full standard is needed if you will be designing your own module.
SCPI 1991
Section 1: Syntax and Style
Section 2: Command Reference
Section 3: Data Interchange Format
Fred Bode, Executive Director
SCPI Consortium
8380 Hercules Drive, Suite P3
La Mesa, CA 91942
Phone: 619-697-8790
Fax: 619-679-5955
======================== VXIplug&play ==========================
The VXI Plug & Play Systems Alliance formed in 1993 and has defined
how instrument drivers will be written so that compatibility from all
vendors will exist.
The Aliance address is:
VXIplug&play Systems Alliance
6504 Bridge Point Parkway
MS: 5610
Austin, Texas 78730
Phone 512-794-5444
Fax:512-794-5569
The VXIplug&play specifications are available on the World Wide Web at:
http://www.vxipnp.org/default.shtml
Here are the sections of the VXIplug&play Spec:
VPP-1: Charter Document
VPP-2: System Frameworks Specification
VPP-3.1: Instrument Drivers Architecture and Design Specification
VPP-3.2: Instrument Driver Functional Body Specification
VPP-3.3: Instrument Driver Interactive Developer Interface Specification
VPP-3.4: Instrument Driver Programmatic Developer Interface Specification
VPP-4.3.2: VISA Implementation Specification for Textual Languages
VPP-4.3.3: VISA Implementation Specification for the G Language
VPP-4.3: The VISA Library
VPP-5: VXI Component Knowledge Base Specification
VPP-6: Installation and Packaging Specification
VPP-7: Soft Front Panel Specification
VPP-8: VXI Module/Mainframe to Receiver Interconnection
VPP-9: Instrument Vendor Abbreviations