Antona ANC-6090 User manual

Antona Corporation [phone]
i
Rev. B
$ 5.00
ANC - 6090
RS-422/485 Serial Communications Adapter
Antona Corporation, Los Angeles, CAAntona Corporation, Los Angeles, CA

Antona Corporation [phone]
1
Antona Corporation
Copyright
Copyright (c) 2003 by Antona Corporation. All rights reserved. No part of this
publication may be reproduced, transmitted, transcribed, stored in a retrieval system, or
translated into any language or computer language, in any form or by any means, electronic,
mechanical, magnetic, optical, chemical, manual or otherwise, without the prior written
permission of the Antona Corporation of Los Angeles, California.
Warranty
Antona Corporation products are warranted to be free from defects in materials and
workmanship for a period of one (1) year from the date of original shipment to customer.
This warranty is limited to the replacement or repair of parts not subjected to misuse,
neglect, unauthorized repair, alteration (except card options), accident, or failure due to the
effects of static electricity discharge.
In no event shall Antona Corporation be liable to the purchaser for loss of use, profit,
or consequential damages, or damages of any kind, including, but not limited to, accidental
loss or damage to other equipment, arising out of use of Antona Corporation equipment,
whether or not said equipment was used properly. The designer is responsible for the
determining the suitability and use of the product.
This warranty is in lieu of any other warranty, expressed, implied, or statutory,
including, without limitation, any implied warranty or merchantability or fitness for a particular
purpose. No amendment of this warranty may be effected except in writing by an officer of
the Antona Corporation.
All repair services shall be performed at the Antona Corporation plant in Los
Angeles, Ca. THE PURCHASER MUST OBTAIN A RETURN
AUTHORIZATION FROM THE ANTONA CORPORATION PRIOR TO
RETURNING ANY PIECE OF EQUIPMENT. Shipment to the Antona Corporation
will be at the expense of the purchaser, return shipment will be at the expense of the
Antona Corporation for all warranty repairs.

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TABLE OF CONTENTS
Features_________________________________________________________________________ 3
Overview ________________________________________________________________________ 3
Mechanical Specifications ________________________________________________________________ 3
Electrical Specifications__________________________________________________________________ 3
Adapter Installation_____________________________________________________________________ 4
Serial Port Powering ____________________________________________________________________ 4
External Powering______________________________________________________________________ 4
Adapter Jumper Options____________________________________________________________ 5
Figure 1 - jumper locations_____________________________________________________________________5
Transmit Control Enable - JP1 ___________________________________________________________ 5
Auto Transmit Source - JP2______________________________________________________________ 6
Photo 1 – RTS Transmit Operation ______________________________________________________________6
Receive Enable - JP3____________________________________________________________________ 6
Cable Termination - JP4_________________________________________________________________ 6
Transmit/Receive Pin Reverse Jumpers – JP5/JP6____________________________________________ 7
figure 2 – Tx/Rc Pin Reverse Jumpers____________________________________________________________7
DCD Drive – JP7_______________________________________________________________________ 7
ANC-6090 External connections _____________________________________________________ 8
DB9 to DB25 pin to pin chart - for use of adapter on a DB25 type com port_______________________ 8
RS-422/485 connections to the ANC-6090 _____________________________________________ 8
DB9 RS-422/485 Signals for Master (Multimedia Controller)___________________________________ 9
DB9 RS-422/485 Signals for Server (Receive from Master) ____________________________________ 9
RS-485 Two and Four Wire Interfacing _______________________________________________ 9
2-wire ________________________________________________________________________________ 9
figure 3 – typical 2-wire RS-485 interface________________________________________________________10
Photo 2 – 2-wire interface example _____________________________________________________________10
4-Wire_______________________________________________________________________________ 10
Appendix A – Troubleshooting Guide ________________________________________________ 11
Loopback Test________________________________________________________________________________11
CABLING (most common problem)_______________________________________________________________11
Pin Signal Definition (4-wire interfaces)___________________________________________________________11
Multidrop Cabling (2-wire interfaces)_____________________________________________________________11
Data Direction Jumpers ________________________________________________________________________12
Signal Control Jumpers_________________________________________________________________________12
Cable Termination ____________________________________________________________________________12
Powering____________________________________________________________________________________12
Program Operation____________________________________________________________________________13
RS422/485 Equipment _________________________________________________________________________13
Plugged in Backwards__________________________________________________________________________13
Now What? __________________________________________________________________________________13
Appendix B -Circuit Board Schematic________________________________________________ 14

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Features
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Overview
The ANC-6090 adapter converts the serial port RS-232C level transmit and receive
signals on an IBM compatible personal computer (Pc), or any device with an RS-232C type
interface, into bipolar-current RS-422 or RS-485 compatible signals. The adapter interface
voltage levels produced meet the EIA-232, TIA-232, RS-422 and RS-485 signals. These
adapters find wide use in high-speed long distance serial communications or to interface a
Pc with equipment that uses an RS-422 or RS-485 type input/output. The adapter is
powered by the host system’s serial port signal lines, the same way a serial port “mouse”
interface is powered. For most installations this eliminates the need for an external power
supply making this adapter an ideal choice for portable use. Extended cable runs and/or
terminated RS-422/485 connections may require more current than the serial port power can
provide so the RS-422/485 connector can accept +3v to +12v regulated DC at 100 milliamps
to provide the added power to drive the adapter.
Mechanical Specifications
Adapter case size: 2.2" X 1.2"
Connectors: Female DB9 to Pc
Female DB9 to RS-422/485 equipment
Electrical Specifications
Power requirements= 6 ma for short cable, non-terminated applications
100 ma for long and/or terminated cable applications
RS-422/485 output drive= short proof output, non-terminated operation to 150 feet,
terminated operation with external power supply to 4000 feet.
RS232 output drive=short proof output, under worse case conditions, ±5v switching
to exceed ±3v EIA RS232 specification

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Adapter Installation
Turn off the personal computer and any other remote equipment before performing
the adapter installation. Never install or remove the adapter with the power applied to
the Pc or any of the attached equipment. This could result in permanent damage to
the adapter due to static discharge.
Normally the adapter is plugged directly into the serial port male DB-9 jack on the
back of the Pc. Be sure to look at the label on the adapter to identify and insure that
the proper DB9 is plugged into the Pc’s serial jack. The ANC-6090 has female DB9s at
both ends. The user should screw the 2 mounting screws into the serial port’s hex nuts for
permanent installations to assure good long-term connection.
The adapter may be attached to a ribbon cable type extension from the Pc to the
Antona adapter. This is sometimes useful when the space is limited behind the Pc. The
ribbon cable extension should not exceed 3 feet. A 12’ shielded wire cable could also be
used. Remember that the signal is still RS-232C level leaving the computer and entering
the adapter. Also note that if the designer is using a DB9 to DB25 adapter an A-B selector
box or break-out box for testing, that all 9 pins should be connected through the adapter or
test setup. The main ANC-6090 adapter power is drawn from the host system’s RTS and
DTR lines, like a mouse interface.
Serial Port Powering
Three of the Pc’s serial port RS-232C level signals can be used by the Antona
adapter to derive power from: RTS, DTR and TX. The user must therefore insure that the
RTS and DTR signals from the Pc’s serial port are brought to a high output level 100 ms
before communicating over the adapter. Usually this is performed once during the user’s
program initialization. When the appropriate jumper is set, RTS is lowered and raised to
transmit and receive respectively for use in 2-wire interfaces.
External Powering
An external DC power source may be feed into pin 9 on the RS-422/485 DB-9
connector to supply the additional current that the adapter may need. The table “RS-
422/485 Connections to the ANC-6090” (page 9) shows the pins for using an external
source of DC to power the adapter. There are also two pads on the circuit board you can
solder leads to for applying external power. A small hole in the plastic case would need to
be added to run the power supply leads away from the adapter. Figure 1 below shows the
pad as black dots. The +3v to +12v regulated DC is soldered to the pin located just to the
right of JP7, and the power supply ground pin is soldered to the pad just above JP4.

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Adapter Jumper Options
Figure 1 - jumper locations
When shipped, the ANC-6090 is set for transmit and receive enabled always.
The output pins are set for ‘master’, the terminating resister is disconnected and RTS
is connected to DCD (JP7).
All references to ‘horizontal’ and ‘vertical’ below are in respect to figure 1
above. The schematic gives another view of each jumper showing the settings on
isolated block drawings of each jumper function.
To open the enclosure hood use a small flat blade screwdriver and carefully pry the
plastic latches on one side of the enclosure and gently separate the sides slightly (about
.020”). Place a paper clip or coin between the separated sides of the enclosure to keep it
from relatching shut while you repeat the process on the two plastic latches on the other
side of the hood. The two sides of the hood should now come apart. The computer side
mounting screws are loose within the enclosure so be careful of these small parts. To
reassemble the enclosure hood back around the adapter electronics, place the circuit board
into the enclosure half that designates signal direction with the RS-422/485 connector (the
DB-9 connector that has the jackscrews) on the arrowed end pointed to by the small
“RS422” designation. Now place the small screws back into position on the RS232, or
computer side, DB-9. Double check that the hood labeled with which end is RS-232 and
RS-422 is properly oriented before pushing the sides together and relatching the plastic
shells. Remember - the RS-422 end of the adapter is the end with the jack nuts mounted
onto the female DB-9 connector.
Transmit Control Enable - JP1
For single adapter 4-wire setups where the ANC-6090 is controlling one piece of
equipment, JP1 can be set in the horizontal position, as shipped, so that the transmit data
RS-422/485 driver lines are always asserted. For battery powered applications, it may be
desirable to turn off the transmit drivers to save current when there is no data being
transmitted using the RTS control line. When using the RTS signal to control the driver
output, the vertical position should be set. See Appendix B, the middle left hand of the
schematic for the location of JP1. The photo 1 below shows how lowering the RTS line on
the RS-232 side of the adapter (lower trace – showing RTS signal after being translated to
the inverted TTL level within the adapter) precedes transmitting the data byte out the TX+
line (upper trace).

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Auto Transmit Source - JP2
This jumper is for the ‘autoxmit’ feature of our ANC-6085 version adapter and is just
left in the horizontal position (as shipped) on the ANC-6090. See Appendix B, the lower left
hand of the schematic for the location of JP2.
Photo 1 – RTS Transmit Operation
RTS may also be used to turn on/off the receive input lines (see JP3 below). When RTS is
used, asserting the RS-232 signal ‘low’ to the adapter enables transmitting while RTS ‘high’
enables receiving. Note that DTR must be set high when RTS is low in order for the
adapter to operate when an external power supply is not being used.
Receive Enable - JP3
This 3-pin straight vertical jumper can be set to enable receiving RS-422/485 data
always (as shipped, JP3 set on the lower and middle pin), or turned off automatically
whenever the transmit driver is set active by RTS (JP3 set on the middle and upper pin).
See Appendix B, the middle left hand of the schematic for the location of JP3. On a 2-wire
interface if data is being transmitted and the receiver is also enabled, anything transmitted
will be ‘looped-back’ into the serial port. Since the echoed signal is the actual data that was
transferred to the interface cable, being able to see the transmitted data echoed back may
be of use for testing, authenticating, diagnostics of data output or determining when RTS
can be lowered if used to control transmission.
Cable Termination - JP4
For installation cable lengths greater than 150 feet, resister termination across the
remote receive pair end of the cable may be necessary. The ANC-6090 has a ½W 120 ohm
termination resister built in that can be placed across the receive wire pair by setting jumper
4 (JP4) located over the transmit/receive setting jumpers. As described above, an external
DC power source may be feed into pin 9 on the RS-422/485 connector to supply the
additional current that the adapter may need when terminating resisters are installed on the
receive/transmit wire pairs. Note that some multimedia equipment have internally connected
circuitry for 120 ohm resister termination. If So, then even if the separation distance is less
than 150 feet, it may be necessary to provide an external source of DC. Some equipment

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also allows the user to disconnect the internal termination network for short cable runs. See
Appendix B, the upper middle of the schematic for the location of JP4.
Transmit/Receive Pin Reverse Jumpers – JP5/JP6
These two jumper sets, designated JP5 and JP6 on the circuit board and schematic,
allow the designer to swap the transmit and receive pairs on the RS-422/485 side of the
adapter. The configuration as shipped from Antona is set for ‘master’. This configuration is
for the adapter acting as a controller to multimedia type equipment with an RS-422 SMPTE
interface. Figure 1 shows the jumper locations from the component side of the circuit board.
The user may move all four jumper shunts on the component side of the card from the
‘horizontal’ controller configuration to the ‘vertical’ receiver configuration. All four shunts
must be changed to either all horizontal or all vertical for proper adapter operation
figure 2 – Tx/Rc Pin Reverse Jumpers
DCD Drive – JP7
This 2-pin jumper disconnects the DCD serial port input line from the RTS signal
output. When not jumpered a small amount of current is saved by not holding the DCD line
high when RTS is high. RTS is one of the two main power sources for the adapter and is
used to control the transmit and receive function in RS-485 type configurations. This jumper
is enabled when shipped by a short trace between the two jumper pads on the solder side of
the PCB. If the designer wishes to disconnect the RTS to DCD connection, just use an
Exacto knife to cut and remove the small trace between the two pads of JP7. Reconnection
may be performed by soldering in a small wire through the two pad holes of JP7. See
Appendix B, the upper middle of the schematic for the location of JP7. Be sure to verify that
the application program either does not rely or use the state of the DCD input pin for
operation.

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ANC-6090 External connections
Signal Function DB-9 Pin # Comment Data Direction
DCD/R
LSD Data Carrier Detect 1Connected via JP7 to RTS input to computer
RX RECEIVE DATA 2RS-232 level input input to computer
TX TRANSMIT DATA 3RS-232 level output output from computer
DTR Data Term Ready 4+v to power
adapter output from computer
GND GROUND 5Signal ground I/O signal ground
DSR Data Set Ready 6Tied to DTR (pin 4) input to computer
RTS Ready to Send 7+v to power
adapter output from computer
CTS Clear to Send 8Tied to RTS (pin 7) input to computer
RI Ring Indicator 9Not connected input to computer
DB9 to DB25 pin to pin chart - for use of adapter on a DB25 type com port
Function DB-9 Pin # DB-25 Pin Comment
DCD/RLSD Data Carrier Detect 1 8
RX RECEIVE DATA 2 3 RS-232 level input
TX TRANSMIT DATA 3 2 RS-232 level output
DTR Data Term Ready 4 20 +v to power adapter
GND GROUND 5 7 signal ground
DSR Data Set Ready 6 6 tied to DTR (pin 4)
RTS Ready to Send 7 4 +v to power adapter
CTS Clear to Send 8 5
RI Ring Indicator 9 22
RS-422/485 connections to the ANC-6090
For multimedia control interfacing, the jumpering of JP5/6 is set for ‘master’ (as
shipped). A 9-pin male to 9-pin male cable wired pin-to-pin is used to connect to the
multimedia device. For other interfaces, the user hand-wires a 9-pin cable assembly from
the RS-422/485 piece of equipment to the Antona adapter with the appropriate pin to signal
interface. The only difference between the ‘master’ and ‘server’ (slave) version is the jumper
positions of JP5 and JP6 within the adapter. The electronics are exactly the same, only the
2 transmit and 2 receive signal lines are exchanged on the RS-422/485 side of the adapter.

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DB9 RS-422/485 Signals for Master (Multimedia Controller)
DB9 CONN (J2) FUNCTION IDENTIFICATION
1GROUND ground for RS-422/485 and/or external
power (same function as pin 5)
2RC- RS-422/485 minus side input
3TX+ RS-422/485 plus side output
4-not used-
5GROUND ground for RS-422/485 and/or external
power (same function as pin 1)
6-not used-
7RC+ RS-422/485 plus side input
8TX- RS-422/485 minus side output
9+V Optional +3V to +12V DC @ 100ma
DB9 RS-422/485 Signals for Server (Receive from Master)
DB9 CONN (J2) FUNCTION IDENTIFICATION
1GROUND ground for RS-422/485 and/or external
power (same function as pin 5)
2TX- RS-422/485 minus side output
3RC+ RS-422/485 plus side input
4-not used-
5GROUND ground for RS-422/485 and/or external
power (same function as pin 1)
6-not used-
7TX+ RS-422/485 plus side output
8RC- RS-422/485 minus side input
9+V Optional +3V to +12V DC @ 100ma
RS-485 Two and Four Wire Interfacing
2-wireUsually a two wire interface with multiple peripherals uses a ‘polled-response’ half-duplex
software protocol where each device has a unique device code. Generally, this requires externally
powering the Antona adapter, but for short cable runs to non-terminated equipment operating at
medium baud rates (like 9600 or less) an external power supply may not be needed. The designer
should use twisted pair wire with a impedance of 100 to 120 ohms. Low-cost CAT-5 UTP
(Unshielded Twisted Pair) wire works fine. The user must externally wire the cable with pin3
connected to pin 7 (TX+ to RC+) and pin 8 to pin 2 (TX- to RC-) on the RS-485 connector side of the
adapter. The 2 conductor cable which connects to the outside world is then wired to pin 7 (+DATA)
and to pin 2 (-DATA) of the RS-485 compatible peripheral (see figure 3 below). We offer an ANC-
CKIT cable kit, with all the hardware needed and 25 feet of CAT-5 UTP wire for this application.

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figure 3 – typical 2-wire RS-485 interface
The photo below (photo 2) shows a typical transmission and reception over an RS-485 2-wire
interface. The top trace shows the data transmitted from the ANC-6090 with a scope probe on the
TX+/RC+ combined line. The2nd group of noisy looking characters is the response received from a
remote device about 4 ms after the last character is sent through the ANC-6090. The lower trace
(#2) shows the RS-232 level signal on pin 2 of the RS-232 DB-9 going back to the Pc after being
cleaned up by the adapter and converted back into a bipolar signal. The9600 baud data depicted
being transmitted and received is through a MODCOM protocol based polled-response type
industrial controller.
Photo 2 – 2-wire interface example
4-WireA 4-wire RS-485 interface uses 2-wires to transmit to all connected peripheral receive
data lines, and 2-wires connected from all peripheral transmit pairs back to the server’s
receive wire pair. In such an arrangement, the server can be transmitting and receiving at
the same time (full duplex) and no ‘polled-response’ protocol or unique device code is
necessary resulting in an overall improvement in communication speed.

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Appendix A – Troubleshooting Guide
RS232/RS422/RS485 Serial Interfaces
Here are the most common sources of interfacing problems and tests you can make to
diagnose your interface:
Loopback Test
You can verify that the Antona adapter is working by doing a simple loopback test using a
male DB9 connector with a wire connection from pin 3 to 7 and pin 8 to 2. You can also add
external power by soldering a 9v battery clip between pin 1 (ground) and pin9 (+V). Use a
simple terminal program to just test that characters sent out the serial port are echoed back
through the adapter. Make sure that your terminal program is turning on RTS and/or DTR to
power the Antona adapter, and that the program is set to control the com port that the
adapter is connected to. Put the signal control jumpers (JP1/2/3) back to default condition if
they have been moved. The adapter operation does not rely on baud rate, parity, stop bits -
but the actual application program you are using with the adapter may (see PROGRAM
OPERATION below).
CABLING (most common problem)
If one of the interface wires used is not connected (open) or shorted, the whole interface
will appear not to be working. Try using another cable or try the loopback test described
above at the end of the cable to verify operation. If you can not get the loopback test to work
through the cable, it will not work in your application. Even cables purchased with molded
ends can be damaged. We test all of the cables we sell before shipping them out.
Pin Signal Definition (4-wire interfaces)
Take a look at the manual of the RS422/485 equipment that you are trying to control. Be
sure that the pin definition on the equipment tells you the signal names, not what they are
suppose to connect to. This sounds simple, but unless you know which direction the pinouts
are defined from, you will connect TX+ to TX+ which is incorrect. Make sure that you have
the TX+ on the Antona adapter connected to the RC+ on the RS422/485 equipment and
TX- connected to RC- (same for the signal coming back from the RS422/485 side -
make sure that the Antona adapter's RC+ is connected to the TX+ and that the RC- is
connected to the TX- on the RS422/485 side. Pin 5 on the Antona adapter's RS422 output
side should be connected to the ground of the RS422/485 equipment.
Multidrop Cabling (2-wire interfaces)
Check to make sure you have connected the ‘plus’ signal lines to the like ‘plus’ signal lines
and ditto for the ‘negative’ to the ‘negative’ signals. Try connecting just one piece of
equipment to the adapter for debugging both the cabling and the software interfacing.
Remember that multidropped peripherals must each be assigned a unique ‘device code’.
Check with the specific equipment’s User’s Manual for setting this, along with protocol,
baudrate, character length, parity and stop bits.

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Data Direction Jumpers
When shipped the Antona adapter is set for a SMPTE MASTER interface. Connector
pinouts are in this manual for both MASTER and SERVER (SLAVE) mode, so be sure you
are looking at the correct table. You may also want to open the Antona adapter up and verify
the jumpers JP5/6 are set for the mode you desire. All 4 jumpers should be installed, they
each represent one of the 4 signals being transmitted and received. The Appendix B
Schematic shows how and where these jumpers are located.
Signal Control Jumpers
There are three main jumpers – JP1/2/3 that control the operation of the signal switching on
the ANC-6090 for transmit and receive enabling. Double check that you have set the
jumpers correctly for your application. All three jumpers must be installed for the adapter to
work properly and it is possible to have one mis-setting cause the adapter to appear non-
operational. Check the adapter jumper settings against the Appendix B schematic (left hand
side). As a baseline, restore all jumper settings to the factory defaults shown on the
schematic.
Cable Termination
Reflected signal produced by cabling that is not terminated properly will cause data
transmission errors. A terminated cable matched to the impedance of the cable wire
produces the maximum signal transfer and dampens the ringing of a reflected signal.
If you are using the adapter to interface with one piece of equipment with a short cable run
(under 150 feet) in an electrically ‘clean’ environment (like an office) then you probably do
not need the cable to be terminated. If on the other hand you are using the ANC-6090 to
interface with 2 or more RS-485 devices in an industrial environment with hundreds of feet of
cable runs – terminating both ends of the cable at the end points would be required. The
adapter has a jumper enabled 120 ohm resister (JP4) that takes care of the adapter end of
the cable. The user must connect a similar resister at the far end of the cable run. An
unterminated cable will not work generally with long cable runs, and baudrates above 2400
baud. Externally powering the adapter for such an application would certainly be
required. The best way to determine if termination is causing your interface not to work is to
just enable the ANC-6090 terminating resister and install a 120 ohm resister onto the last
piece of RS-485 equipment on the cable. Check also, that you have not over-terminated the
cable by having more than two resisters installed other than one at each end of the cable
run. Access one end of the cable and use a multimeter set to the 200 ohm scale. You
should measure about 60 ohms if there are two 120 ohm resisters in parallel across the
cable. If you are using multiple Antona adapter’s, only one at each end of the cable should
have JP4 enabled. Likewise, check any other piece(s) of equipment on the cable to make
sure if they contain termination resisters that only one of them is enabled at the end of the
cable.
Powering
Be sure that the RTS and/or DTR line on your RS232 interface are high - this is what
powers the Antona adapter (like a mouse interface). Some portable computers just do not
have enough power to run the adapter and/or the RS422/485 piece of equipment you are
interfacing. Or it may be over a long cable run and/or terminated with a 120 ohm resister.
You can try disconnecting the termination resister also - some types of equipment, like the
ANC-6090, give you a jumper option (JP4) for enabling the termination resister. It might be

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necessary to externally power the adapter through the RS422/485 side by applying +3v to
+12v DC power to pin 9 and ground to pin 5 or 1.
Program Operation
The application program you are using may need some setup performed - selecting the
serial com port, baud rate, parity, number of data bits, stop bits and setting the level of the
handshaking signals (RTS and DTR lines high to power the adapter). Usually, for multimedia
type interfaces, the baud rate is 38.4 Kbaud, Odd parity, 8 data bits and 1 stop bit. For
many RS-485 multidrop industrial control applications, the baud rate is much slower, like
9600, no parity, 8 data bits and 1 stop bit. Here again, if the program is not setup right, the
adapter will appear not to be working at all.
RS422/485 Equipment
Try to verify the operation of the target equipment independent of the Antona adapter by
using another setup - a different cable connected to another RS422/485 signal generating
device would be the best. Using a different computer with the Antona adapter would also be
a good test.
Plugged in Backwards
The adapter is shipped with a set of jumpers preset for the most common configuration,
sometimes, after a customer has opened the adapter, changed some settings to suit their
application, the adapter’s plastic shell will be refitted around the adapter backwards to the
label indications. This mistake is easy to do as both ends of the adapter have a female DB-
9. If in doubt, note that the end with the jack-nuts is the RS-422/485 end of the adapter. We
have had adapters returned as broken, which were fine, except the shell had been put on
backward.
Now What?
If none of the above seems to fix the problem, but the loopback test works, the adapter is
working and you may now need to connect an oscilloscope up to examine and monitor the
RS422/485 signals and the RS232 signals being generated by the Antona adapter with the
plastic cover removed and running with your RS422 device and program. Refer to the
schematic, Appendix B in this manual. It is easy to put a scope probe onto the tops of the 4
jumpers (JP5/6) and verify that RS422/485 signals are coming and going to the adapter.
Test the +power to the adapter by attaching a probe to the +lead of the 22uf capacitor near
the +3v regulator. Look for excess noise on any of the lines that might be fouling up the
transmissions.
If the loopback test does not work, connect a temporary external power supply up to the
adapter by using a +9v battery and battery clip wired onto the loopback connector described
above. Each adapter is tested prior to shipment with every combination of character
transmitted and received at 38.4 Kbaud, but like everything, occasionally they can go bad.
Of the hundreds we have shipped, there have been maybe 10 or so that arrived non-
operational. Damaged in shipping or infant component burnout. We do warranty our
adapters, so if it still does not work, call Antona and we will work out an adapter exchange.

Antona Corporation [phone]
14
Appendix B -Circuit Board Schematic
The following page contains the schematic for the 6090 adapter. The schematic and
card artwork are copyright protected by Antona Corporation and are included only to aid the
end user to configure the adapter or for competent technical service personnel to use in
maintenance or repair.
Note: The schematic is included with the purchase of the product.