PCI20U
Universal V oltage PCI Bus ARCNET® Network Interface Modules
INST ALLA TION GUIDE
INTRODUCTION
The PCI20U series of ARCNET network interface modules (NIMs) links
PCI and PCI-X bus compatible computers with the ARCNET local area
network (LAN). Since most PC motherboards have migrated from the +5 V
PCI Bus to the +3.3V PCI Bus, a universal voltage PCI NIM is required. In
addition, the PCI20U series supports the PCI Add-in card specification.
Both standard height and low-profile brackets are provided. The PCI Bus
allows for jumperless configuration and Plug and Play operation. The module
operates with either an NDIS driver or a null stack driver in a Windows
environment. DOS drivers will operate when used with our enabler software.
Since the PCI20U is a universal voltage PCI card it can be used in either a
PCI-X slot or a conventional PCI slot. PCI-X is an enhancement to the
original PCI Local Bus Specification enabling devices to operate at speeds up
to 133 MHz. If a PCI20U is installed into a bus capable of PCI-X operation,
the clock remains at the 33 MHz frequency and other devices on that bus are
restricted to using conventional PCI protocol.
The PCI20U incorporates the COM20022 ARCNET controller chip with
enhanced features over the earlier generation ARCNET chips. New features
include command chaining, sequential access to internal RAM, duplicate node
ID detection and variable data rates up to 10 Mbps. Bus contention problems
are minimized since the module’s interrupt level and I/O base address are
assigned through Plug and Play . There is no requirement for wait-state
arbitration.
®
The PCI20U exploits the new features of the COM20022. This includes
10 Mbps communications utilizing the various EIA-485 transceiver options.
Each PCI20U module has two LEDs on the board for monitoring network
operation and bus access to the module. It is equipped with an 8 position,
general purpose DIP switch typically used to assign the ARCNET node
address. Ultimately, the node address is configured via software so the DIP
switch can also indicate user-defined functions such as data rate, cable
interface, or master/slave status of the system.
There are several versions of the PCI20U ARCNET NIM. Three models sup-
port traditional ARCNET 2.5 Mbps di-pulse transceivers. The PCI20U-CXS
supports coaxial star or point-to-point configurations facilitated by the use of
active hubs. The PCI20U-CXB supports coaxial bus configurations while the
PCI20U-TB5 supports twisted pair bus configurations using RJ-45 connectors.
Both bus topology products usually do not require active hubs. Four models
also support EIA-485 networks and both standard mode and backplane mode
are supported. The PCI20U-485 (backplane mode) and PCI20U-485D (nonbackplane mode) support DC-coupled operation. The PCI20U-4000 (backplane) and PCI20U-485X (non-backplane) support AC-coupled operation.
SPECIFICATIONS
Environmental
Operating temperature: 0°C to +60°C
Storage temperature: –40°C to +85°C
Data Rates
PCI20U-CXB, -CXS, -TB5 2.5 Mbps
-485D
PCI20U-
PCI20U-4000, -485X 10 Mbps, 5 Mbps, 2.5 Mbps, 1.25 Mbps
Dimensions Shipping W eight
2.50" x 4.72" 1 lb. (.45 kg)
(64 mm x 120 mm)
I/O Mapping
Requires 16 bytes of I/O space for COM20022 controller
485, 10 Mbps, 5 Mbps, 2.5 Mbps, 1.25 Mbps,
625 kbps, 312.5 kbps, 156.25 kbps
Interrupt Lines
Supports PCI INT A
Compatibility
PCI20U series NIMs are fully compatible with all of Contemporary Controls
(CC) ARCNET products and PCI Bus computers.
Regulatory Compliance
CE Mark; CFR 47 Part 15 Class A
Power Requirements
Model +5 V +3.3 V
PCI20U-4000 400 mA 30 mA 20 mA
PCI20U-485
PCI20U-485D
PCI20U-485X
PCI20U-CXB
PCI20U-CXS
PCI20U-TB5
400 mA 30 mA 20 mA
400 mA 30 mA 20 mA
400 mA 30 mA 20 mA
400 mA 30 mA 20 mA
400 mA 30 mA 20 mA
400 mA 30 mA 20 mA
V I/O
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INSTALLATION
The PCI20U can be installed in any PCI Bus compatible computer. With the
power detached from the computer, remove the cover of the computer—
exposing the motherboard and expansion slots (connectors). Care should be
taken when installing the PCI20U because both it and the exposed computer
motherboard are sensitive to electrostatic discharge. To prevent inadvertent
damage, touch the metal case of the internal power supply to discharge
yourself then proceed to remove the PCI20U from its protective ESD
package. Remove the backplate of the computer adjacent to the desired slot
(connector). The PCI20U can then be inserted into this slot by applying a
downward even pressure until it stops and is firmly seated into the connector.
The PCI20U backplate can be secured to the computer by installing the small
screw used to attach the original backplate. Hardware installation is
completed by replacing the computer cover.
Software Drivers
Unlike ISA Bus computers, PCI Bus computers frequently have their
resources assigned by the operating system. The PCI20U requires a 16-byte
I/O range for the COM20022 ARCNET controller and one interrupt line.
Depending upon the sophistication of the software driver, the PCI20U
assignment may be done automatically by the driver with little concern on
the part of the user. This is called Plug and Play operation. Some software
drivers, especially those originally written for ISA bus computers, may not
verify resource allocation automatically— requiring the user to accomplish
this task. This is called jumperless operation. It is important that the user
appreciate the type of software driver being used since it is sometimes
difficult to remove software drivers once they are installed.
OEM Software Driver
If the PCI20U has been specified by an Original Equipment Manufacturer
(OEM) for use with their equipment, follow the instructions of the OEM and
utilize their driver disk.
Microsoft® Networking
If your intention is to use Microsoft Networking with Windows 95, 98, NT
or 2000, you will require an NDIS 4.0 driver. Obtain this driver from our web
site and follow the instructions on its use. This is a Plug and Play driver so it
is unnecessary to use our enabler software or verify resources. With this
driver you can operate with the various transport layers supported by
Microsoft including TCP/IP.
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Legacy ISA Software Driver
The PCI20U is register compatible with our PCX20 ISA adapter, PC10420
PC/104 adapter, PCM20 PC card adapter, as well as SMSC’s COM20020
Evaluation Board. If the software driver was originally written for the ISA
or PC104 versions of these adapters and the intent is to operate this same
driver using the PCI20U under Windows 95, 98 or ME, then enabler software
is required to map the system resources to the I/O and interrupt requirements
of the legacy driver. The required enabler software is available on our web
site. Only use this software when a Plug and Play driver does not exist.
Follow the instructions in the README.TXT file (which can be found in the
enabler file set) before attempting an installation of this software.
Other Operating Systems
With Windows NT/2K/XP, you must have a Plug and Play driver. The enabler
software cannot be used. For other operating systems such as Linux or QNX,
view our web site for the latest support on these operating systems.
Node ID Switch
Although not always necessary with the COM20022, the PCI20U provides a
separate input port that reads an 8-bit DIP switch (SW1) located at the top
edge of the module. This switch is intended to serve as a node ID switch,
although it can serve as a general purpose switch if desired. The node ID
switch has no connection to the COM20022 ARCNET controller chip.
The most significant bit (MSB) is switch position 1, and the least significant
bit (LSB) is switch position 8. A switch in the open position (off position or
away from the printed circuit board) introduces a logic “1”. Figure 1 shows
the node ID switch. In this example the switch is set to hexadecimal
address F5.
32
1
87654
MSB
Figure 1 — Node ID Switch
LSB
Indicator Lights
There are two LEDs located at the PCI20U backplate. The yellow LED
indicates that the PCI20U is being accessed via its I/O address. The green
LED indicates that the PCI20U is transmitting ARCNET traffic to the
network.
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FIELD CONNECTIONS
The PCI20U is available in several transceiver options. Each transceiver,
which is matched to a particular cable type, is identified by a suffix appended
to the model numbers. The capabilities of each transceiver differs.
Figure 2 — A hub is required to extend bus segments.
-CXB Coaxial Bus
For hubless systems, the -CXB transceiver can be used. NIMs are
interconnected with RG-62/u cables and BNC T ee connectors. Each -CXB
NIM represents a high-impedance connection in both the powered and
unpowered states. Therefore, passive termination must be applied to both
ends of a bus segment. Use BNC-style 93 (nominal) ohm resistors at each
end. The maximum segment length is 1000 feet and the maximum number of
NIMs that can be connected to a segment is eight.
T o extend a bus segment beyond 1000 feet, an active hub is required. If the
hub port is of the -CXS type, connection can be made if a few simple rules
are followed. Only connect this type of hub at the end of a segment. Do not
connect the hub to the middle of a segment since the hub port is not of the
high impedance type. Do not terminate the end which attaches to the hub
port since a -CXS port effectively terminates the end of a bus segment.
Simply remove the BNC T ee connector and terminator from the segment end
and attach the cable directly to the hub port. The opposite segment end still
requires termination if no hub connection is being made.
-CXS Coaxial Star
In a coaxial star system, NIMs and hubs are interconnected in a point-to-point
fashion using coaxial cable. A NIM can connect to one other NIM or can
connect to an unused port on a hub. Hub-to-hub connections are allowed.
In a two-node system, simply connect the two -CXS NIMs together using
RG-62/u coaxial cable. The length of cable cannot exceed 2000 feet.
If more than two NIMs are used on a network, either an active or passive hub
is required. With passive hubs, a maximum of four NIMs can be interconnected.
Unused ports on the passive hub must be terminated with a 93 ohm (nominal)
resistor. The maximum length allowed between a passive hub port and a NIM
is 100 feet.
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Active hubs provide overall better performance than passive hubs since
greater distances can be achieved along with a degree of isolation. Connect
each NIM to a port on the hub using RG-62/u coaxial cable. This length of
cable cannot exceed 2000 feet nor can the length of cable between two
cascaded hubs exceed 2000 feet. However, up to ten hubs can be cascaded
thereby providing an overall cable length of 22,000 feet. Unused ports on
active hubs need not be terminated.
PORT1
PORT2
PORT3PORT3
Figure 3 — Point-to-point connections are required
between -CXS NIMs and hubs
-TB5 T wisted-Pair Bus
The -CXB transceiver can be modified to drive a balanced cable system with
the addition of some parts. This configuration is called -TB5 and it supports
shielded or unshielded twisted-pair cable such as Category 5. Dual RJ-45
connectors replace the single BNC connector in order to support the popular
modular plug connectors. Follow the connector pin assignments in Table 2
when using this connector or when mixing cable types. Wiring between NIMs
is accomplished in a daisy-chain fashion with point-to-point cables
connecting the various NIMs to create a bus segment. The end NIMs will
have one vacant RJ-45 socket which is to hold the RJ-45 style 100-ohm
terminator required to terminate the end points of the bus segment. Use
twisted-pair cable and observe polarity. Modular plugs must be installed on
this cable such that they do not invert the signals. Most satin cable does not
twist the pairs nor maintain signal polarity. Do not use this cable. To test the
proper cable connections, hold both ends of the cable side by side with the
retaining clips facing the same direction. The color of the wire in the right-most
position of each plug must be the same if there is no inversion of the cable. If
this is not the case, the cable is inverted. Up to eight -TB5 NIMs can be
connected to one segment which cannot exceed 400 feet in length.
The overall distance of a twisted-pair network can be expanded beyond 400
feet if hubs are used. Use a hub port that supports the same -TB5 interface.
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Figure 4 — TB5 NIMs are connected in a daisy-chain fashion.
-485D DC-Coupled EIA-485 (Non-Backplane Mode)
The PCI20U-485D supports DC-coupled EIA-485 communication via a
daughter board which replaces the coaxial hybrid transceiver. This daughter
board receives the conventional P1 and P2
pulses intended for the coaxial hybrid
transceiver and converts them to an elongated
P1 pulse (the width is equal to P1 and P2)
suitable for the EIA-485 differential driver .
Therefore, do not set the COM20022 to
backplane mode for EIA-485 communication as
recommended in Standard Microsystems
Corporation’s (SMSC) application note and
data sheet since CC implements the same
signaling on this daughter board. With our
approach, the same software driver used for
coaxial networks will function with the
EIA-485 version of the PCI20U without modification.
On each NIM, one three-position screw terminal (see Figure 6) connector
provides a convenient daisy-chain connection for attaching multiple nodes
onto one segment. Make sure that the phase integrity of the wiring remains
intact. Be sure to use the proper cable. Refer to Table 3 for connector pin
assignments.
Termination
12345678
Figure 5 — Modular Jack
Numbering Orientation
Each end of the segment must be terminated
in the characteristic impedance
of the cable. A 120-ohm resistor can be
invoked with a jumper which resides on the
EIA-485 daughter board. With the middle
jumper inserted at location E1 on the
daughter board, 120 ohms of resistance is
applied across the twisted-pair (Figure 7).
With the jumper removed, no termination is
applied. If external termination is desired,
remove this jumper and install a 120-ohm 1/4 watt resistor across pins 1 and 2
on the screw terminal connector. Incorporating a resistance value less than
120 ohms is not recommended since it may excessively load the EIA-485
transceivers.
Table 2 — Modular Connector
Pin Assignments
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Bias
In addition to the termination, it is also necessary to apply bias to the
twisted-pair network so that when the line is floated, differential receivers
will not assume an invalid logic state. There are two precision bias resistors
(Rb) of equal value on each daughter board. One resistor is tied to the +5 V
line and the other is tied to ground. Each resistor has a jumper associated with
it. If the two jumpers are installed, the resistor tied to +5 V is connected to
the (+) signal line while the grounded resistor is connected to the (–) line. This
voltage drop will bias the differential receivers into the “1” state when no
differential drivers are enabled. Differential receivers typically switch at or
near zero volts differential and are guaranteed to switch at +/–200 mV.
Through the transition point, 70 mV of hysteresis will be experienced.
Therefore, a positive bias of 200 mV or greater will ensure a defined state. W e
recommend that bias be applied to both ends of the wiring segment by
installing the two end jumpers located at position E1 on the daughter board.
This is to be done for only the two NIMs located at the end of the segment.
All other NIMs will have their jumpers removed.
The termination and bias rules are simple. If the NIM is located at the
extreme ends of the segment, install all three jumpers at location E1 on the
daughter board. If the NIM is located between the two end NIMs, remove all
three jumpers. If external
termination is desired, remove
the middle jumper at E1.
For EIA-485 DC operation, it
is very important that all
Table 3 — Screw T erminal Connector Pin
Assignments for -485, -485D and -485X
the common mode voltage requirement (+/–7 Vdc) of the EIA-485
specification is achieved. This can be accomplished by running a separate
ground wire between all computers or by relying upon the third wire ground
of the power connector assuming that the DC power return is connected to
chassis ground on the computer. Another approach would be to connect the
DC common of each computer to a cold water pipe. Connected systems, each
with different elevated grounds, can cause unreliable communications or can
damage the EIA-485 differential drivers. Therefore, it is important that an
adequate grounding method be implemented. A ground connection can be
found at pin 3 of the screw terminal connector.
devices on the wiring segment
be referenced to the same
ground potential in order that
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Segments of -485D connected NIMs can be
extended through the use of active hubs. Select
an AI Series hub or repeater with a -485D
compatible port. Connect one end of the
segment to this port following the same
termination rules as used for a NIM. This hub
port counts as one NIM when cable loading
is being calculated. The NIM electrically
closest to the hub port should not have any
termination or bias applied. Follow the same
rules for other segments attached to different
Figure 6 — Screw
T erminal Connector
Numbering Orientation
hub ports. Maintain the same cabling polarity
as the NIMs by using cable connections that do not invert the signals.
-485X AC-Coupled EIA-485
The AC-coupled EIA-485 transceiver offers advantages over DC-coupled
EIA-485. No bias adjustments are needed since each transceiver has its own
fixed bias network isolated by a pulse transformer. Unlike the DC-coupled
EIA-485, wiring polarity is unimportant. Either inverted or straight-through
cable can be used or even mixed within one AC-coupled network. Much
higher common mode voltage levels can be achieved with AC coupling due to
the transformer coupling which has a 1000 Vdc breakdown rating.
There are disadvantages to the AC-coupled transceiver as compared to the
DC-coupled technology . The DC-coupled distances are longer (900 feet)
than the AC-coupled distance (700 feet)1. The AC-coupled transceiver will
operate at 1.25, 2.5, 5.0 and 10 Mbps while the DC-coupled transceiver will
operate over all seven data rates.
The cabling rules of the -485X are similar to the -485D. One three-position
screw terminal connector is provided to attach network cabling. Wire a
maximum of 13 NIMs in a daisy-chain fashion. On the end NIMs insert a
jumper at E1 on both -485X daughter boards to invoke 120-ohm termination
resistors (Figure 7). Termination can also be accomplished by installing a
120-ohm, ¼ watt resistor across pins 1 and 2 of the screw terminals at each
end of the bus segment. Refer to Table 3 for connector pin assignments.
Termination should not be applied to any of the NIMs located between the
two end NIMs of the segment. Do not mix -485D and -485X NIMs together
on one segment; however, bridging of the technologies is possible using active
hubs with the appropriate transceivers. To extend -485X segments, use a hub
as discussed under the -485D section. Make sure the active hub transceivers
are of the -485X type. Cable inversion is not of any consequence.
1
Distance figures based on 2.5 Mbps operation.
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-4000 AC-Coupled EIA-485 (backplane mode)
The -4000 transceiver is used when backplane mode operation is desired. It is
similar to the -485X transceiver in operation but has some subtle differences.
A maximum of 8 NIMs may be connected on a single bus segment with up to
262 feet of twisted-pair cable. T ermination can be accomplished by installing
a TB5-TER, RJ-45 terminator in the unused RJ-45 jack.
For 485X only
E1
E1
For 485D only
Figure 7 — Jumper settings for EIA-485 models.
-485 DC-Coupled EIA-485 (backplane mode)
The -485 transceiver is used when backplane mode operation is desired. All
operating parameters are the same as the -485D transceiver except that the
COM20022 is set for backplame mode operation. Refer to the -485D section
for operating details.
Electromagnetic Compatibility
The PCI20U series complies with Class A radiated and conducted emissions
as defined by CFR 47 Part 15 and EN55022. This equipment is intended for
use in non-residential areas.
Warning
This is a Class A product as defined in EN55022. In a domestic
environment this product may cause radio interference in which case
the user may be required to take adequate measures.
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NEED MORE HELP INSTALLING THIS PRODUCT?
More information can be found on our web site at www.ccontrols.com. Browse
the Technical Support section of our site for a look at our on-line technical
manuals, downloadable software drivers and utility programs that can test
the product. When contacting us, just ask for technical support.
Warranty
Contemporary Controls (CC) warrants its new product to the original purchaser for two years from the product shipping date. Product returned to CC
for repair is warranted for one year from the date that the repaired product is
shipped back to the purchaser or for the remainder of the original warranty
period, whichever is longer.
If a CC product fails to operate in compliance with its specification during the
warranty period, CC will, at its option, repair or replace the product at no
charge. The customer is, however, responsible for shipping the product; CC
assumes no responsibility for the product until it is received.
CC’s limited warranty covers products only as delivered and does not cover
repair of products that have been damaged by abuse, accident, disaster, misuse, or incorrect installation. User modification may void the warranty if the
product is damaged by the modification, in which case this warranty does not
cover repair or replacement.
This warranty in no way warrants suitability of the product for any specific
application. IN NO EVENT WILL CC BE LIABLE FOR ANY DAMAGES
INCLUDING LOST PROFITS, LOST SAVINGS, OR OTHER INCIDENTAL
OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR
INABILITY TO USE THE PRODUCT EVEN IF CC HAS BEEN ADVISED
OF THE POSSIBILITY OF SUCH DAMAGES, OR FOR ANY CLAIM BY
ANY PARTY OTHER THAN THE PURCHASER.
THE ABOVE WARRANTY IS IN LIEU OF ANY AND ALL OTHER
WARRANTIES, EXPRESSED OR IMPLIED OR STATUTORY, INCLUDING THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR
PARTICULAR PURPOSE OR USE, TITLE AND NONINFRINGEMENT.
Returning Products for Repair
Return the product to the location from which it was purchased by following
the instructions at the URL below:
www.ccontrols.com/rma.htm
DECLARATION OF CONFORMITY
Information about the regulatory compliance of this product can be found at the
URL below:
www.ccontrols.com/compliance.htm
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