© 2000 STANDARD MICROSYSTEMS CORPORATION (SMSC)
80 Arkay Drive
Hauppauge, NY 11788
(631) 435-6000
FAX (631) 273-3123
Circuit diagrams utilizing SMSC products are included as a means of illustrating typical applications; consequently complete information sufficient for
construction purposes is not necessarily given. The information has been carefully checked and is believed to be entirely reliable. However, no
responsibility is assumed for inaccuracies. Furthermore, such information does not convey to the purchaser of the semiconduc tor devices described
any licenses under the patent rights of SMSC or others. SMSC reserves the right to make changes to specifications and product descriptions at any
time without notice in order to improve design and supply the best product possible. Contact your local SMSC sales office to obtain the latest
specifications before placing your product order. The product may contain design defects or errors known as anomalies which may cause the
product’s functions to deviate from published specifications. Anomaly sheets are available upon request. SMSC products are not designed, intended,
authorized or warranted for use in any life support or other application where product failure could cause or contribute to personal injury or severe
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of the customer. Copies of this document or other SMSC literature may be obtained by visiting SMSC’s website at http://www.smsc.com
SMSC UG - EVB-20019
Page 2
Rev. 1/5/00
EVB-20019
Industrial ARCNET
AT Adapter Card
•
Based on COM20019 Rev. B Industrial Network
Controller
•
Supports both standard and backplane signaling
schemes
•
COAX and UTP support for standard ARCNET signaling
in both bus and star topologies
•
Isolated and direct RS485 interfaces
•
All media interfaces are jumper selectable
•
Data rates from 19 Kbps to 312 Kbps
•
8 bit, I/O mapped bus interface, I/O address is switch
selectable
•
Programmable DMA channel
•
On-board node ID switch
•
Capable of receiving all packets
•
Includes demo software
•
Sample driver, network monitor and mapping routes
APPLICATIONS:
Test equipment, network development and debug,
network management/monitoring, network evaluation,
performance analysis
SMSC UG - EVB-20019
Page 3
Rev. 1/5/00
USER’S MANUAL FOR EVB-20019 INDUSTRIAL ARCNET ADAPTER CARD
I/O Address Selection
The EVB-20019 is an 8 bit I/O mapped card. The I/O address is selected via DIP switch S1. The switch positions
correspond to address bits A9 – A3. The switch is factory set for address 2E0h. If you encounter problems
accessing the card then you must change the value of the address. To set the address simply set the switch
according the binary representation of that address. For example, address 2E0h would be 1011100. The network
controller uses addresses XX0 – XX7 and address XX8 selects the Node ID switch (S2).
Node ID Selection
The EVB-20019 is equipped with an on-board Node ID switch mapped at address XX8. The COM20019 network
controller requires a software programmable ID, therefore the switch does not automatically provide a Node ID to the
COM20019. The switch only provides a value to be programmed by the software.
Media Interfaces (Transceivers)
The EVB-20019 supports three types of media interfaces: direct coupled RS-485, and isolated RS-485 (twisted pair)
ports and twisted pair TMCAC RS-485 line interfaces.
Direct Coupled RS-485
The Direct Coupled RS-485 interface uses a RJ-11 connector with Phase A on pin 2 and Phase B on pin 3.
Recommended cable is 24AWG unshielded twisted pair such as Belden #9562. Biasing resistors are
provided (470 ohms) for squelching of reflections. A 75ALS176B transceiver is used. Short stubs or drops
of less than one foot can be accommodated but are not recommended. Data rates from 19 Kbps to 312
Kbps are allowed. Note that the Direct Coupled RS-485 interface is not compatible with either the isolated
RS-485 or the standard ARCNET twisted pair interface.
Isolated RS-485
The Isolated RS-485 interface employs transformer coupling to electrically isolate the data lines and make
the connections insensitive to polarity. Isolation is provided up to 2KV. Data rates from 19 Kbps to 312
Kbps are accommodated. Connections are made via pin 2 and 3 of the RJ-11 connectors. Note that the
isolated 485 transceiver utilizes a different modulation technique than the direct coupled scheme and should
not be mixed with direct coupled interfaces or with the standard ARCNET twisted pair interface.
TMC AC RS-485
The AC power RS-485 is an optional transceiver interface.
Jumpers
There are three sets of jumper blocks on the EVB-20019 board. JP1-4 selects the clock speed of the network
controller. JP1 and JP2 MUST BE INSTALLED for proper operation. JP3 and JP4 are for future use and should be
left unconnected. JP9, JP10, JP11 and JP19 select the source of data for the network controller’s receiver. JP15-17
are used to choose the media type. Refer to the following table for the correct jumper settings:
MEDIA TYPE
Direct RS-485
Isolated RS-485
TMC AC RS-485
Interrupts
If your software is to be interrupt driven, the priority of the interrupt is selected through JP5-JP8 (IRQ3-6).
CONNECT JUMPERS
JP9, JP12, JP13
JP10, JP14, JP15
JP19, JP22, JP23
SMSC UG - EVB-20019
Page 4
Rev. 1/5/00
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