Synapse SNAP Link User manual

USER GUIDE
SNAP Link
Serial Wireless Adapter
RS-232 and RS-485 Devices
©2008-2014 Synapse, All Rights Reserved. All Synapse products are patent pending. Synapse, the
Synapse logo, SNAP, and Portal are all registered trademarks of Synapse Wireless, Inc.
Doc# 600038-01D
6723 Odyssey Drive // Huntsville, AL 35806 // [phone] // Synapse-Wireless.com

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Table of Contents
1. About Your SNAP Link Wireless Adapters ................................................................... 1
2. Setting Up Your SNAP Link Wireless Adapters............................................................. 3
Modes of Operaon......................................................................................................................... 3
SNAP Link State Indicators............................................................................................................... 3
Changing SNAP Link States .............................................................................................................. 4
3. SNAP Link EasySet Software ....................................................................................... 7
Installing EasySet.............................................................................................................................. 7
Using EasySet ................................................................................................................................... 8
Connect a SNAP Link Device ............................................................................................................ 8
Selecng Basic Communicaons Sengs........................................................................................ 9
4. Configuring your Adaptor using the DIP Switches...................................................... 15
DIP Switch 1 ................................................................................................................................... 15
DIP Switch 2 ................................................................................................................................... 16
5. Application Usage Scenarios..................................................................................... 17
Scenario 1: Card Scanner ............................................................................................................... 17
Scenario 2: File Transfer, Connuous Stream................................................................................ 17
Scenario 3: Lowest Latency at Highest Baud Rate......................................................................... 18
6. Troubleshooting....................................................................................................... 19
7. Frequently Asked Questions ..................................................................................... 21
Appendix A Mounting Options ....................................................................................... 23
Appendix B Modbus Firmware ....................................................................................... 24
Appendix C Advanced Management ............................................................................... 25

1. About Your SNAP Link Wireless Adapters
SNAP Link Adapters
The SNAP Link family of industrial-class, mesh networking, wireless serial adapters allows you to connect RS-232
and RS-485/422 devices to each other without using cables. SNAP Link adapters provide the highest data-rates,
longest distance, and most reliable signal in the industry.
SNAP Link devices are available in two models:
•SL232K-001 –RS-232 with 250 Kbps wireless data rate
•SL232K-002 – Adds DC power opon to 001 version
•SL485K-001 –RS-485/422 with 250 Kbps wireless data rate
•SL485K-002 – Adds DC power opon to 001 version
Each SNAP Link adapter comes with SNAP EasySet, an intuive applicaon program that runs on Microso®
Windows®-based computers that allows you to configure the device quickly and easily. Please refer to soware
specificaons in the appendix of this document for exact operang system requirements.
You can also configure your SNAP Link adapters using internal DIP switches in the event a computer running
EasySet is not available.
Key Features of SNAP Link
•Features SNAP® — the Synapse Network Applicaon Protocol — instant-on, self-healing, mesh network
operang system.
•Available with wireless data rates up to 2 Mbps.
•Supports wireless RS-232, RS-422, and RS-485 transparent serial data transfers.
•Hardened Modbus wireless protocol included for 99.5% reliable transport.
•Enables simple, one buon pairing for fast, easy installaon.
•Supports one-to-one (point-to-point) and one-to-many (mulpoint) relaonships.
•Performs mesh hopping, which can extend distances across many miles.
•Includes SNAP Link EasySet soware for advanced configuraons.
•Requires no changes to exisng equipment and soware.
Document Convenons
Please note the following terminology while reading this document:
•The term SNAP Link is used to refer to any of the SNAP Link models listed above.
•The RS-232 models are referred to by their model number, which is SL232. This pertains to both models
unless otherwise noted.
•The RS-485/422 models are referred to by their model number, which is SL485. This pertains to both
models unless otherwise noted.
•The term K-series refers to the SL232K and SL485K adapters.
•The term serial port refers to the data communicaons port – either the RS-232 port (DB9F connector)
of an SL232 device or the RS-485/422 terminal block of an SL485 device.
SNAP Link 1

•The micro-B USB port of the SNAP Link adapter may be referred to as simply the USB port.
•The term RS-485/422 device or RS-232 device refers to the data communicaons device you are
aaching to the SNAP Link adapter.
•The term UART Parameter refers to SNAP Link configuraon sengs that indicate how quickly data is
wirelessly transmied based on serial data that is received from the serial device.
•The term, Modbus Firmware, refers to a Modbus protocol reliability script that can be uploaded to a
SNAP Link model using EasySet soware V1.2.2 or higher.
Download Supporng Materials
Documentaon pertaining to SNAP Link devices can be downloaded from the Synapse Wireless website at:
synapse-wireless.com/index.php?mainID=3&subID=11&type=product&prodID=11
The SNAP Link User Guide (the document you are reading now) can be downloaded at:
synapse-wireless.com/documents/products/SNAP_Link_User_Guide.pdf
The Synapse SNAP EasySet configuraon soware can be downloaded at:
synapse-wireless.com/documents/apps/EasySet-setup.exe
2SNAP Link

2. Seng Up Your SNAP Link Wireless Adapters
Refer to your SNAP Link Quick Start Guide accompanying your SNAP Link wireless adapter for illustraons
showing you how to set it up quickly. This chapter gives you more detail about the various modes of operaon
and the three indicator lights.
Modes of Operaon
SNAP Link units are powered via a USB cable through their micro-B USB connector. They can be powered by
connecng a USB cable to the supplied AC adapter, or by plugging the cable into the USB port of a computer. It
will be necessary to use a computer’s USB port if you wish to configure your SNAP Link units using the EasySet
soware, which is described in the next chapter.
All models of SNAP Link can operate in either point-to-point mode, also known as unicast, or in mulpoint mode,
also known as mulcast. In point-to-point mode two SNAP Link units are paired, thereby providing a wireless
connecon between two external serial devices. In mulpoint mode, one of the SNAP Link devices is designated
the master and mulple other devices can be configured as slaves. This secon provides more detail on how
these modes can be set manually by pressing the MODE buon on the SNAP Link device.
SNAP Link State Indicators
You can change the state of your adapter either by holding down the MODE buon or by pressing it in rapid
succession.
There are three LEDs on a SNAP Link device. LED A is located on the front next to the MODE buon. LEDs B and C
are located on the back panel between the micro-B USB and serial connectors.
Set from the factory, these three LEDs communicate various configuraon sengs or traffic status events as
documented next, unless the Modbus firmware script has been uploaded to the SNAP Link adapter.
Note: The three LEDs perform differently when the Modbus hardened reliability firmware has been
installed, as documented in the Modbus Firmware Appendix
The A LED indicates the wireless broadcast state. It can be off, green, amber or red, and can be steady or flashing
depending upon the current status or mode of operaon:
•When the unit is seeking a pair the LED will rapidly flash red.
•When the unit is paired, either in unicast mode or as a slave in mulcast mode, the LED will glow
steadily. Green indicates a strong wireless signal, amber indicates a weak signal, and red indicates no
signal or loss of signal from its partner. No maer what the color, the LED will flicker while wireless
transmission is occurring.
•When the unit is in mulpoint mode and is seeking a master, the LED will rapidly flash amber.
•When the unit is set up as a master, the LED will slowly alternate between green and amber.
•If a master detects another master on the same channel and network, the LED will slowly alternate
between red and amber.
The B LED indicates the USB state. Green indicates the unit is being supplied with power. It will glow steadily in
idle and will flicker when data is being transferred via the USB port.
The C LED indicates the serial interface state. If an RS-232 device is aached to the DB9F connector of the SL232
adapter, the LED will glow steadily green in idle and will flicker as data is being transferred. If an RS- 484/422
SNAP Link 3

device is aached to the terminal bock of the SL485 adapter, the LED will not glow, but will flicker as data is
being transferred.
Note: It may be difficult to differenate an amber colored LED from one showing green or red, depending
upon your viewing angle. When viewed from above, an amber LED may look red and when viewed from
below it might look green. If in doubt, try viewing the LED at different angles.
Changing SNAP Link States
When a SNAP Link device is inially powered on, its serial communicaons parameters are set to factory
defaults. This inial state is called broadcast state, because at this point SNAP Link hasn’t been paired with
another unit. However, it will join and become a member of a greater SNAP mesh network. Most commonly,
each SNAP Link device will be married to, or paired with, another SNAP Link.
The factory default serial port sengs for all SNAP Link devices is 9600 baud, 8 data bits, no parity, and 1 stop
bit. For SL232 devices flow control is disabled, and for SL485 devices flow control is always enabled. The SNAP
network ID is set to 0x1C2C and the channel number is set to 4. Many of these can be altered using EasySet or
by using a bank of DIP switches located on the SNAP Link circuit board inside the unit, as shown in the chapter
Configuring your Adaptor using the DIP Switches.‖ Reseng a unit causes the SNAP Link device to read the DIP
switches and set itself accordingly.
Reset a unit, or
return it to
broadcast state
Broadcast state is the inial SNAP Link state as set by the factory. To return to broadcast
state, remove power, hold down the MODE buon, then reapply power. Aer 5 seconds,
when all LEDs are rapidly flashing green-amber-red, release the MODE buon. The B LED
will be green, signifying power. The C LED will be green only if an RS-232 device is aached.
The A LED, which signifies broadcast state, will be off.
Pair a unit in
point-to-point
While in broadcast state, hold down the MODE buon for at least 5 seconds. When LED A
turns red, release the MODE buon. The unit will then look for another SNAP Link to pair
with, as indicated by the LED rapidly flashing red. When it finds a partner, the A LED will
glow steadily. Green indicates a strong signal from the partner, amber indicates a weak
signal, and red indicates no signal (the partner is powered off or else is out of range).
Note: A SNAP Link adapter will only pair with another adapter that is also seeking a
pair. So you must perform the above procedure on two SNAP Link adapters
simultaneously to form a pairing.
Back out of
searching for a
pair
While LED A is rapidly flashing red, hold down the MODE buon for at least 5 seconds. LED
A should go dark. Release the MODE buon and the unit is now back in broadcast state.
Remove pairing Hold down the MODE buon for at least 5 seconds. When LED A turns red, release the
MODE buon. The unit drop any current pairing and will then begin looking for another
SNAP Link unit with which to pair.
Set a unit to
mulpoint mode
While in broadcast state, press the MODE buon 4 mes in rapid succession (within 3
seconds). LED A will rapidly flash amber. The unit is now in mulpoint mode and will begin
looking for a master to pair with. If it finds one, it will pair with it and the A LED will glow
steady, but will flicker as data is transmied.
4SNAP Link

Set up a unit as a
mulpoint master
While in mulpoint mode, again press the MODE buon 4 mes in rapid succession. LED A
will then blink slowly, alternang between green and amber, indicang the unit is the
master in a mulpoint network. Any slave units on the same channel and with the same
network ID, which were previously set to mulpoint mode, will then begin pairing with the
master. If LED A should begin alternang between red and amber, that indicates another
master is already on the same channel and with the same network ID.
Back out of
mulpoint mode
when previously
set up as a master
If the unit was previously set up as a master, press and hold the MODE buon (for at least
5 seconds) unl LED A rapidly flashes. The unit is no longer a master, but is sll in
mulpoint mode, and is now looking for a master with which to pair.
Back out of
mulpoint mode
altogether
If the unit was previously set up as a master, first back out by following the procedure
above. Then, press and hold the MODE buon again (for at least 5 seconds) unl LED A
glows steadily. Release and the unit is now back in broadcast state. It can now be set up in
point-to-point mode or in mulpoint mode.
Pin Outs
RS-232 (DB9F) Pin Outs
The SL232 adapter provides a DB9 female connector with the following pin outs:
RS-232 PIN OUTS
Arrows indicate signal direcon
The SL232 adapter uses a standard DB9 female connector configured as a DCE (Data Communicaons
Equipment) device. A DCE device can be connected to a DTE (Data Terminal Equipment) device using a straight
through serial cable. A computer is typically defined as a DTE and communicaons peripherals, such as the
SL232, are defined as a DCE. To connect a DCE with another DCE, or DTE to another DTE, a null modem adapter,
or crossover cable, is required. The null modem adapter swaps certain pins, typically pins 2 and 3, and 7 and 8,
to convert a DCE into a DTE and vice-versa.
SNAP Link 5

RS-485/422 Pin Outs
The SL485 adapter can operate in either 2-wire mode or 4-wire mode according to the following pin outs:
TWO-WIRE MODE FOUR-WIRE MODE
A terminal block is provided to which the transmit (TX), receive (RX), and ground (GND) wires can be aached.
The factory default is set to 2-wire, but can be changed using the DIP switches located on the circuit board inside
the adapter case. See the chapter ―Configuring your Adaptor using the DIP Switches‖ for details in seng the
DIP switches.
To wire a connecon in two-wire mode, pick a pair of TX/RX pins – either 1 and 2 or 3 and 4. If your applicaon
requires a ground wire, somemes referred to as 3-wire or 5-wire, then also include pin 5.
6SNAP Link

3. SNAP Link EasySet Soware
Synapse has developed an intuive soware applicaon to help you configure your SNAP Link adapter. This
soware, known as SNAP EasySet, provides a graphical interface to access sengs such as baud rate, flow
control, and parity bits.
EasySet is currently available for Microso Windows XP (SP2) or newer and Windows 7 operang systems, and
can be downloaded from the Synapse Wireless website at:
synapse-wireless.com/documents/apps/EasySet-setup.exe
Aer downloading the soware launch the installer to guide you through the installaon process.
Installing EasySet
Upon launching the installer, this dialog is presented.
Click Next to connue and follow the on screen
installaon instrucons. First specify where EasySet
should be installed, the default being the Synapse
folder within Program Files. Then press Install and
the soware will be installed to the specified
locaon.
This dialog gives you the opon to exclude certain
components.
SNAP Link 7

During installaon you’re asked to disconnect any
Synapse USB devices. This is so the installer can load new
drivers. Disconnect any Synapse USB devices and press Ok
to complete the installaon.
Using EasySet
Launch EasySet by selecng EasySet from the Windows Start menu.
EasySet will start up and present this window.
You will see four icons in the tool bar across the top of the window. Most
of these are inacve (grayed out) unl EasySet is connected with a SNAP
Link adapter. There are also four tabs in a tab bar below the tool bar.
Toolbar
The four toolbar commands are:
Connect / Disconnect Serial Port – used to connect and disconnect from the aached SNAP Link device.
Because this icon changes when you connect or disconnect, it also serves as a quick status indicator.
Ping – causes EasySet to make a quick connecvity test to the aached SNAP Link device.
Refresh Node Informaon – causes EasySet to poll the aached SNAP Link device for configuraon
informaon.
Upload SNAPpy Image – prompts EasySet to upload the SNAP Link operang soware into the
aached SNAP Link device. It will be necessary to do this only upon release of new SNAP Link soware,
or upon instrucon by technical support.
Connect a SNAP Link Device
Connect a SNAP Link device to your computer using the supplied USB cable. The micro-B side of the cable fits
into the back of the SNAP Link device and the USB end fits into any standard USB port on your PC. This
connecon supplies power to the SNAP Link and also allows EasySet to communicate with it.
Next, tell EasySet to scan the computer’s communicaons ports for a Synapse device. Press the Connect Serial
Port buon and EasySet will scan all serial ports and will stop when it believes it has found a SNAP Link device.
8SNAP Link

When EasySet finds a Synapse device, press the
Connect buon. If it failed to find the correct
device type, press the Scan buon to the right of
the port idenfier. This will cause EasySet to
connue the scan.
If EasySet finds an aached device, but it’s not a SNAP Link, then
you will see this error message. Press Ok and then Scan again.
When successfully connected to a SNAP Link device, EasySet
populates the communicaon fields with the data currently set in
the SNAP Link device.
When the SNAP Link device is powered up for the first me, you will see the factory default sengs set
internally by the DIP switches. Once the configuraon is changed by EasySet, the SNAP Link device will retain the
new configuraon in flash memory.
Tab Bar
There are four tabs across the top of the window – Basic, UART, Pairing, and Advanced – which allow you to
match the communicaons sengs of your SNAP Link adapter to that of the serial communicaons device to
which you are connecng.
Selecng Basic Communicaons Sengs
Below the icons and immediately above the tab bar is the SNAP Link
adapter type: either RS-232 or RS-485/422. To the right of that is the
adapter’s MAC (media access control) address. The same address is also
printed on a label on the boom of the device.
Set the items under the Basic tab to match those of the serial
communicaons device you are connecng to your SNAP Link adapter. In
this example we are aaching a device running at 9600 baud with 8 data
bits, no parity, 1 stop bit, and with flow control enabled.
Network ID
The network ID can be thought of as a logical channel. This 16-bit integer may be assigned any
hexadecimal value from 0x0001 through 0xFFFE. Devices in a SNAP network must share both
the same channel and same network ID to communicate. This allows mulple SNAP networks
to share the same channel if required, although it is preferred to place independent networks
on separate physical channels to reduce collisions. SNAP Link defaults to network ID 0x1C2C.
Channel
The channel number can range from 0 to 15. All SNAP Link devices that you wish to include in
the same network must be set to idencal channel numbers. Due to FCC regulaons, channel
15 provides slightly less output power than channels 0 to 14. Hence, in most cases it is
recommended to avoid using channel 15.
SNAP Link 9

Data UART
SNAP Link adapters contain two UARTs (Universal Asynchronous Receiver/Transmier), one
for the USB port and one for the serial communicaons (RS-232 or RS-485/422) port. This
seng indicates which port is connected to your serial device, therefore defining where the
serial data should be transmied. The factory default is to send all serial data through either
the RS-232 DB9 or RS-485/422 terminal block and NOT through the USB cable. The default
seng of the USB port is to communicate only with EasySet.
You can change this arrangement, but doing so will make your device unreachable via the USB
port for further programming by EasySet. If you choose "USB" using this Data UART seng in
EasySet and later need to reprogram the device, the easiest method is to reset the device,
thereby seng it back to its default sengs.
Baud Rate
Set the SNAP Link baud rate to match that of your serial device. The baud rate for all devices
can range from 0 to 115,200. While K-series adapters can send chunks of data in bursts up to
115,200, they safely sustain a maximum of 19,200 baud. M-series adapter can sustain large
data transfers at speeds up to 115,200 baud.
Data Bits Set the number of data bits to 7 or 8.
Parity Set the parity to none, odd, or even.
Stop Bits Stop bits is always 1 for K-series adapters and can be 1 or 2 for the M-series adapters.
Flow Control If your device uses flow control, then this seng should be enabled. Otherwise, this seng
should be disabled.
Note: EasySet Versions earlier than V1.2.3 had three parameters shown on the Basic tab: Mesh Roung
Seng, Mesh Roung Maximum Timeout and Mesh Override. These parameters are now located on the
Mesh Tab in EasySet versions 1.2.3 and higher.
Mesh Settings - Custom
Mesh Roung Seng
Synapse nodes on the same channel and same network communicate with each
other using mesh roung. This means any device can communicate with any
other device (they are all logical peers within the mesh) even though in some
cases units that are out of radio range with each other might have to pass
messages through intermediate nodes.
10 SNAP Link

Mesh roung can be enabled, disabled, or set to custom. Enable mesh roung to
allow a SNAP Link device to parcipate as a node in a wider SNAP mesh network.
Mesh Roung Maximum
Timeout
If you set Mesh Roung to custom, then the maximum age, in milliseconds, can
be specified here. The default value should cover most network topologies and
should be changed only under the direcon of technical support. Be careful
when changing these values on remote nodes as you could make it impossible to
communicate with the node remotely.
Mesh Override
If you set Mesh Roung to custom, then check this box to indicate mesh
override. This means to use mesh roung, but not to route for other nodes in the
network.
Mul-Cast Forwarded
Group
Select ―On‖ to have the connected SNAP Link adapter re-transmit or re-
broadcast any communicaons it receives from the Master. This is typically
enabled on a SNAP Link client mode adapter located approximately halfway
between the Master unit and the SNAP Link adapter client that exhibits poor
transmission signal strength behavior as documented in the chapter called
Troubleshoong.
Mesh Roung Inial Hop
Limit
Select ―One‖ to have the connected SNAP Link adapter limit Hops to ―1‖. A hop
limit of ―1‖ directs a SNAP Link unit to request roung paths from other SNAP
devices one hop away. It will automacally aempt to discover a roung path up
to five hops away, if this inial one hop discovery fails. By seng this parameter
to zero (―0‖), you are telling the SNAP Link aached adapter to aempt sending
a packet directly to the address first, before seeing if there is a route path to get
to him. This seng is most useful when fast ming is required and you are
prey sure they are within one hop distance.
Mesh Reject Link Quality
From (dBm)
The Mesh Reject Link Quality slider allows you to require the minimum signal
strength, as measured in dBm strength, that the connected SNAP Link adapter is
allowed to use for transming to a neighboring node, even if the neighboring
node is the Master device.
WARNING: seng this slider to the far right could result in an oddly
behaving mesh network, including no connecon success at all. dBm is a
logarithmic seng from 0 to -127 and the slide allows you to require the
minimum signal strength to be between -100 (weak) to -50 (very strong).
Sliding it to the le may allow more packets to become lost, never
arriving at its desnaon. Sliding it to the right will decrease the number
of these dropped packets, but may result in no communicaon at all if
set too far to the right.
Mulcast TTL
(Master Seng)
Mulcast Time-To-Live parameter only needs to be set on the SNAP Link adapter
designated as the Master. As discussed in other secons, Master transmissions
use the Mulcast protocol in order for mulple clients to all receive the Master
transmissions. By default, Mulcast TTL has been set to ―1‖, which means that
even if a Client adapter’s Mesh Roung Inial Hop Limit is set to ―On‖, they will
SNAP Link 11

not retransmit or rebroadcast the Master’s transmissions. Example: There are
four SNAP Link adapters in a long linear line: Master, Client1, Client2 and Client3.
Master node transmissions do not get to the farthest Client (3), but it appears
Client1 could get it to Client2 and Client2 could get it to Client3 since each Client
is about 1/3 of the distance away from its neighbors. In this example, seng the
Master TTL to 4 on the Master adapter and seng Client 1 and Client 2 to ―On‖
for the Mesh Roung Inial Hop Limit should make sure all transmissions are
received.
Note: If you sll have issues, please review the Modbus Firmware
appendix.
Mesh – No Mesh
Mesh Roung Sengs – No Mesh
Seng the Mesh Roung Sengs parameter to ―No Mesh‖ keeps
transmissions to a minimum, reducing interference and collisions that may add
lag, or delays, in the smooth ming operaon of your SNAP Link adapters
(somemes referred to as a ―broadcast storm‖). Only enable mesh roung if
you have determined that you need some of your Client mode adapters to help
retransmit or rebroadcast transmissions in order for all Clients to receive and
transmit their informaon.
Mesh – Mesh Defaults
Mesh Roung Sengs - Mesh
These are the default parameters when you select ―Mesh‖from the Mesh
Roung Sengs pull down menu. Selecng Mesh indicates that you want the
connected SNAP Link adapter to assume an addional role of ―transmission
repeater/router‖. As long as the Master adapter has the Mulcast TTL (Master
Seng) assigned to a number larger than 1, all nodes with this ―Mesh‖ pull down menu selecon will repeat
unicast and mulcast transmissions they receive.
Modbus Firmware (If Script has been loaded)
Modbus Firmware
A new tab called ―Modbus‖ has been added in the release of EasySet
V1.2.3 once a SNAP Link adapter has Uploaded the ―Modbus‖ script and
reset to factory default. The new Firmware field denotes this connected
SNAP Link adapter has had the script uploaded by displaying ―Modbus‖
along with a new Modbus tab. The Modbus script enables a new hardened
wireless Modbus protocol that provides the highest reliability transport
along with the ability to fine-tune the retransmissions and lag or latency
introduced by those retries. Please review the Modbus appendix later in
this document for more informaon.
12 SNAP Link

UART Settings
The UART tab contains three parameters allowing you to fine tune data
transmission. These can be set according to the needs of the serial device.
You may have to adjust these, depending upon transmission speed and the
size of data packets. See the chapter on Applicaon Usage Scenarios for more
help in seng these parameters.
Buffering Timeout
This seng controls the overall serial data meout. The value is in
milliseconds with the default being 0, or no meout.
The Buffering Timeout controls the elapsed me between an inial character
being received and a packet of serial data being enqueued for processing.
When the meout passes, regardless of the number of characters buffered or
the rate at which they are received, the buffered data will be sent. The larger
this value, the more buffering that will take place. However, while this allows
for more data to be sent per packet, which might be more efficient depending upon your applicaon, it also
increases latency.
Note that other events, controlled by Buffering Threshold and Inter- character Timeout, can also trigger the
buffer of data to be sent.
Buffering Threshold
This seng indicates the maximum packet size used when sending data. The default is 100 bytes and the
maximum is 123 bytes. Values over 100 are not recommended as they could result in buffer overrun.
Buffering Threshold causes buffered data to be sent whenever the threshold is reached. However, triggering the
Buffering Timeout or Inter-character Timeout sengs could cause data to be sent before the threshold is
reached.
Each packet of data includes a header, which comprises 12 bytes for mulpoint packets and 15 bytes for point-
to-point packets. So, the actual number of data bytes sent will be either 12 or 15 bytes fewer.
If you set Buffering Threshold to a large number, then larger, more efficient packets will be sent, but with
greater latency. At higher baud rates seng this value too high can result in dropped characters.
Inter-character Timeout
This seng allows you to tune the inter-character serial data meout. This value is in milliseconds and defaults
to 10.
Inter-character Timeout is the maximum elapsed me that should pass before sending the enqueued packet
aer receiving a character. It restarts with every received character. This parameter or Buffering Timeout can
trigger transmission of buffered data before Buffering Threshold is reached. Conversely, if the meouts are high
or disabled altogether, then data will be transmied when the Buffering Threshold is reached.
Seng a large Inter-character Timeout can give beer mulcast transparent mode reliability but with greater
latency.
SNAP Link 13

Pairing Settings
The Pairing tab indicates whether the SNAP Link adapter is paired with
another adapter, which is denoted by displaying the other pair's SNAP
address.
State
This is the paired state. The value can be:
•Simple Broadcast – Unit is in a reset state and is waing to be set up.
•Searching for Master – Unit is in mulpoint mode and is searching for
a master unit with which to pair.
•Master – Unit is in mulpoint mode and is the master. It is now willing to accept slave units.
•Slave – Unit is in mulpoint mode, is a slave, and has paired with a master.
•Ready to Pair – Unit is in point-to-point mode and is looking for another unit with which to pair.
•Paired – Unit is in point-to-point mode and has been paired with another.
Address of Pair
When paired, this will be the device address the unit is paired with. If a slave, this will be the address of the
master. If a master, this field will be blank.
Time Between Status Messages
The number of seconds between pings. The device will periodically ping its partner to confirm connecvity.
Advanced Settings
The Advanced tab contains a single checkbox labelled Buon Lockout. When
checked, the MODE buon on the front of the SNAP Link adapter will be
disabled. However, the MODE buon can sll be used to perform a reset,
pung the SNAP Link device back into broadcast state.
14 SNAP Link

4. Configuring your Adaptor using the DIP Switches
You use the MODE buon on the front panel of your SNAP Link adapter to define which SNAP Link adapters
communicate with each other, as discussed in earlier secons of this manual. You use the EasySet soware to
modify the enre range of parameters, also as discussed in earlier secons of this manual.
However, if you do not have access to a computer running EasySet, you can configure some communicaon
parameters using the DIP switches located inside the unit.
Changing DIP switch sengs will override the default parameters, or parameters previously configured using the
EasySet soware. However, EasySet can also override the DIP switch sengs. SNAP Link adaptors have built-in
intelligence to determine if EasySet or the DIP switches were last used to change the configuraon. The general
rule is: the last method used to change the sengs is the one that takes precedence.
SL232 has a set of 8 internal switches that set Flow Control, Baud Rate, and SNAP Channel.
SL484 has the same set of 8 switches plus a second set of 6 switches that configure the device for either 2- wire
or 4-wire operaon.
To access the DIP switches, remove the four screws on the antenna end of the device and slide out the enclosed
PC board to expose the switches.
DIP Switch 1
DIP switch 1 consists of 8 individual switches, which are applicable to all SNAP Link devices. All possible switch
sengs are shown in the tables below. This example indicates flow control off, 2400 BAUD, and SNAP channel 9.
Switch
Seng
Flow
Control
Switch Seng Baud
Rate
Switch Seng SNAP
Channel
4 3 2 8 7 6 5
0 - off Disabled 0 0 0 9600 0 0 0 0 0
1 - on Enabled 0 0 1 19,200 0 0 0 1 1
0 1 0 38,400 0 0 1 0 2
0 1 1 57,600 0 0 1 1 3
SNAP Link 15

1 0 0 115,200 0 1 0 0 4
1 0 1 300 0 1 0 1 5
1 1 0 1200 0 1 1 0 6
1 1 1 2400 0 1 1 1 7
1 0 0 0 8
1 0 0 1 9
1 0 1 0 10
1 0 1 1 11
1 1 0 0 12
1 1 0 1 13
1 1 1 0 14
1 1 1 1 15
DIP Switch 2
DIP switch 2 consists of 6 individual switches and is present
only in SL485 devices. It is used to configure the device for 2-
wire or 4-wire operaon. Note that 2- wire is always half
duplex and 4-wire can be switched between half or full
duplex. RS-422 is always 4-wire, full duplex.
Switch 1 2 3 4 5 6
2-Wire Half Duplex 1 1 0 1 1 0
4-Wire Half Duplex 0 0 1 1 1 0
4 Wire Full Duplex 0 0 1 1 0 1
RS-422 0 0 0 1 0 1
Some device manufacturers might refer to these as 3-wire or 5-wire. This is referring to the same sengs
described above, but are including the ground wire in their specificaon.
16 SNAP Link