Product data
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CompactPCI
MEN CompactPCI
PXI System Controllers
CompactPCI Single-Board Computers can in general be used as PXI
system controllers as well. Nevertheless, many of MEN’s 6U and 3U
x86 or PowerPC-based CompactPCI SBCs are equipped with
additional PXI trigger lines in accordance with the PXI specification.
M-Modules – I/O for PXI Systems
M-Modules in PXI Systems. M-Modules are especially well
suited for instrumentation tasks. The board space provided for
components allows implementation of complex instrumentation
functions and this also includes the best signal isolation possible,
using onboard DC/DC converters. The generous space provided for
dedicated connectors guarantees protection of sensitive signals. The
simple and cost-effective architecture of the M-Module interface
results in optimum cost-per-channel.
Front Panel I/O. M-Modules offer direct front panel connection
rather than requiring a separate adapter panel with flat cable
connections. This provides a clean path for sensitive signals without
loss of data or signal quality-using, for example, shielded D-Sub
connectors and COAX cables.
M-Module Interface. A fast asynchronous parallel interface
offers sophisticated functions such as 32-bit data bus, burst transfers
up to 100MB/s, DMA and trigger capabilities. The simple
architecture of the M-Module interface allows the development of
M-Modules within very short time.
M-Module PXI Carrier Cards. The carrier card for 6U systems
can accommodate up to four M-Modules, while the carrier cards for
3U systems come with one or two M-Module slots.
All carrier cards support five PXI trigger lines with two onboard
trigger sources (one-shot or continuous trigger; 243Hz..5.33MHz
frequency). They also have flexible trigger routing: First, the on-
board trigger sources may be routed to the M-Module interface or
to the PXI trigger lines. Second, the PXI trigger lines may be routed
to the M-Module interface trigger lines and vice versa.
Prepared for Harsh Environments. In order to meet rugged
mounting requirements, M-Modules can be fixed to the carrier
board using four screws. Air flow and cooling are optimized in order
to make M-Modules suitable for the industrial operation temperature
range of -40 to +85°C.
ANSI Standard. M-Modules are ANSI standard since 1997
(ANSI/VITA 12). The full specification is available from www.vita.com
and www.ansi.org.
PXI Software Support
PXI requires that all peripheral modules have device driver software
that runs in the appropriate framework. For all M-Modules MEN
supports National Instrument’s LabWindows/CVI based on
Windows.
Support of LabWindows/CVI is included in MDIS4 (MEN Driver
Interface System) for Windows. MDIS4 is a standard interface layer
for most M-Modules. Together with a specific application note, the
MDIS4 system package and the low-level M-Module drivers can be
downloaded from MEN’s web site for free.
LabWindows/CVI support is also included for M-Modules with native
Windows drivers.
In addition, user-ready standard IVI drivers for M-Modules are
available for the instrument classes of switches, multimeters and
function generators.
Organization of a PXI system
System
Controller
Local Bus
Star Trigger
Trigger Bus
132 Mb/s, 33 MHz, 32-bit computer Bus
Peripheral Peripheral
Star Trigger
Controller
Peripheral
10 MHz
CLK
PXI trigger
routing on M-Module carrier cards
Desktop PC packaging is not always suited to the demanding industrial environments envisioned for new instrument designs.
PCs were not designed for industrial environments, and therefore do not provide the connectivity, cooling support, EMI resistance,
and the slot capacity needed for many high-performance instrumentation systems.
To solve these problems, the PXI standard (PCI eXtensions for Instrumentation) was developed in 1998 defining additional trigger
lines on top of the CompactPCI standard. In fact, most PXI products are fully interoperable with CompactPCI products.
In development and bench top instrument applications, the most economical way to use PXI instruments is with a desktop PC for
control and a host-to-slave link for connection to the PXI modules. For many other applications, the PXI instruments will ultimately
reside in a rack with other equipment such as on a factory floor or remote site or where portable operation is desired. In these
settings the use of desktop PCs is not feasible and an embedded PC must be used. A monitor and keyboard may be attached to the
controller for development or debugging and then removed or replaced with a LAN connection for later use. This configuration is
somewhat higher in cost but allows the highest flexibility in operational setting and smaller system size.
PXI in Instrumentation
TRIGB
CompactPCI Backplane
D203
TRIGA
D203
PXI_TRIG[0]
PXI_TRIG[0]