ACCES I/O Products, Inc.
MADE IN THE USA
mPCIe-ICM422-4
3
manual revision A1h
C
HAPTER
5:
PC
I
NTERFACE
This product interfaces with a PC using a PCI Express Mini Card
(mPCIe) connection; a small-form-factor, high-performance,
rugged peripheral interconnect technology first introduced for use
in laptops and other portable computers.
mPCIe’s small s
ize and powerful performance, combined with
perfect software compatibility with PCI and PCIe peripheral
designs, have led to its recent adoption as a go-to standard for
embedded Data Acquisition and Control, and many other
applications.
Although mPCIe is a broadly-adopted industry standard, the actual
connection to the computer shares a specification with mSATA:
both mSATA and mPCIe use the same edge-connector. In fact,
well-designed PCs can automatically detect and configure their
onboard connectors to work with either mPCIe or mSATA devices
–
and, according to the standards for mPCIe and mSATA they are
supposed
to do so! However, some PC manufacturers ship
computers that
only
support mSATA devices. Please confirm in
your PC documentation that your edge-connector is
actually
PCI
Express Mini Card compliant before installing this, or any, mPCIe
card. Damage might occur if you install an mPCIe device into a
computer that only supports mSATA.
mPCIe defines mounting holes for securing the otherwise loose
end of the card, so it is impossible for these cards to wiggle or flap
themselves loose (which was a recurring problem with the older
PCI Mini devices). Eliminating this concern for PCI Express Mini
Cards is a major reason this standard has seen rapid adoption by
the Data Acquisition and Control industry.
The mPCIe standard, like its PCI Mini Card predecessor, was
designed assuming use primarily in Laptop or Notebook and similar
devices, where physical dimension is often the paramount design
constraint. In Data Acquisition and Control applications low-weight
combined with vibration tolerance tend to be of more concern.
Caution: Although the 2-Port card is fully compliant with all
standard dimensions for a full-length mPCIe design, the 4-port card
violates the component-height limit on the back of the card, by up
to 1.3mm. This may result in mechanical incompatibility with some
motherboard designs, if, and only if, they place other motherboard
components inside the footprint of the full-length mPCIe card.
C
HAPTER
6:
I/O
I
NTERFACE
This card provides one 5-pin latching Hirose DF57
connector per serial port. The mating connector is
the Hirose DF57H-5S-1.2C. Order the CAB-mPCIe-4S
or
–
2S cable kit accessory to cable the DF57
connectors to industry standard DB9 Male
connectors. Alternately, custom hardware interfaces
can be produced to fit your specific application
requirement.
The DF57 connector is a low profile latching device. In order to
operate it correctly, please note: the front of the cable connector
clicks down, into a locked position,
after
the rear has been mated
by pushing it into the socket. To disconnect, pop the front of the
cable connector upwards to
disengage the latch before moving
the connector away from the card.
C
HAPTER
7:
S
OFTWARE
I
NTERFACE
Although the UARTs provided by this card are fully 16550/16950
compatible, the advanced features are best enabled by using the
provided software drivers.
The card installs ports into the OS as standard serial COM devices.
Therefore, in each OS or programming environment, standard
COM APIs are used to communicate. For example, in the .NET
Common Language Runtime you would use the methods provided
by the System.IO.Ports namespace. In Linux, the ttyS
n
device
controls port
n
. Other operating systems have similar, OS-specific,
standard methods of communication with serial devices.
Various sample programs are provided to demonstrate application
programming of the serial ports, in a variety of popular
programming languages.
WinRISC is a Windows serial port utility provided with this card. It is
very useful when working with any serial device: it provides a very
simple, very easy, interface.
Important
: It is necessary to disable "hardware handshaking" (DTR)
in your communication program when operating in RS485 or
RS422 mode.
The latest information can always be found on the product page on
the website. Here are some useful links:
Hirose
5-pin
422
1
GND
2
Rx+
3
Tx+
4
Rx-
5
Tx-
DB-9
Male Pin
422
1
Tx-
2
Tx+
3
Rx+
4
Rx-
5
GND
6
7
Rx-
1
8
9
Note 1: pin 4 and pin 7 are
connected.
