|
|
Digital PCI Express Board
Named Editor’s Choice
 |
Named a June 2009 Editor’s Choice pick by VME
and Critical Systems magazine, the 8004e PCI Express X1 digital I/O
interface provides 16 optically isolated inputs and 16 Reed relay
outputs. |
- Optically isolated inputs protect the PC from voltage
spikes commonly found in industrial environments
- The Reed relays provide long-life, dry contact switch
closures that are suitable for low current applications
- Reed relays are normally open and close when energized
Read about the 8004e (rated for 3-13V input) and
the 8004He (rated for 10-30V input) PCI Express digital I/O adapters.
Low Profile PCIe Interface with Two Ports & Wide Range of Baud Rates
 The low-profile PCI Express serial interface (Item#
7205e) provides two configurable serial ports that utilize a 16C950
UART with 128-byte Tx/Rx FIFOs, which enables data rates to 921.6K
bps for reliable high-speed communications in data-intensive applications.
Each port is individually configurable for RS-232, RS-422, or RS-485.
- Oscillator and clock prescaler support wide range of
baud rates
- Supports 9-bit protocol framing and data rates to 921.6K
bps
-
Includes a 36” cable with two DB9M connectors
Read about the low profile 7205e and the standard size 7205eS.
|
Tech Lowdown
PCI Express: Lanes Explained
PCI Express cards communicate with the host processor using
two pairs (one transmit, one receive) of low voltage serial signal connections
called “lanes”. The connection from the host processor to a PCIe
peripheral, the “link”, can consist of a single lane (X1) or
up to 32 lanes (X32). Common questions involving compatibility between devices
with different lane sizes are: “Can I use a Sealevel PCIe X1 serial
card in a PCIe X16 slot?” and “Will a PCIe X16 video card work
in a PCIe X4 location?” The PCI Express specification was designed
with compatibility in mind, so each of these scenarios is supported:
-
 A PCIe expansion card will work in any slot
with at least as many lanes as it contains. So, X1 cards will work
in any PCI Express slots.
- An expansion card with a larger number of lanes
will work in an expansion slot with a smaller number of lanes provided
it fits mechanically.
In this case the expansion card will throttle back to the number of lanes
supported by the expansion slot, so the performance will decrease. Adapters
are available to help accommodate this configuration.
|
|
|
|
