SNAP2410/2414/2420 Spread Spectrum Network Access Points Installation Guide April 20, 2000 One Meca Way Norcross, Georgia 30093 www.digital-wireless.
Note: This unit has been tested and found to comply with the limits for a class A digital device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instruction manual, may cause harmful interference to radio communications.
Table of Contents Introduction ...................................................................................................... 1 Getting Started ................................................................................................. 2 Connecting the SNAP .................................................................................... 2 SNAP Status Indicators ................................................................................. 3 Configuring the SNAP..........................
INTRODUCTION The SNAP2410 family of products from Digital Wireless Corporation provides Ethernet connectivity to networks of WIT2410 radios. Built around the WIT2410, SNAP products provide a 10BaseT connection to Ethernet networks and function as base stations for remote devices containing WIT2410 transceivers. By supporting seamless roaming, multiple SNAPs can be connected to a network to provide practically unlimited coverage area.
GETTING STARTED The SNAP family of wireless Ethernet modems are easy to install and operate. In most instances, the only installation steps will be setting IP addresses, selecting one modem as the master and connecting the antenna, power and Ethernet cable. Connecting the SNAP Figure 1 identifies the various connectors on the rear of the SNAP2410. Power Connector Synchronizing Signals 10BaseT Ethernet Connector TNC Antenna Connector Figure 1.
Power Switch Status Indicators Configuration Port SNAP 2410 2.4 GHz SPREAD SPECTRUM WIRELESS ETHERNET MODEM Figure 2. SNAP2410 Front Panel Diagram The Configuration Port is an RS-232 serial port that may be used to configure the SNAP. This is useful when the default IP address of the SNAP cannot be used with the existing network preventing configuration through a telnet session. See the section Configuring the SNAP for details of using this port.
problems on the network and that the SNAP will be recognized by the network. If the default IP address conflicts with a device on the existing network, the SNAP will need to be configured through the serial port. The SNAP can be configured two ways. The first is through the serial port. The settings for the serial port are 38400 baud, 8 data bits, 1 stop bit, and no parity. WinSNAP will automatically find the appropriate serial port and configure the serial port settings for you.
SNAP OPERATION Overview At the most basic level, SNAPs can be thought of as Ethernet-to-serial interface adapters. That is, they take data from a host application over a 10BaseT Ethernet connection, remove the Ethernet header information, format the data for WIT2410 radios and transmit the data to the on-board WIT2410 through a high-speed serial interface. In the other data flow direction, the on-board WIT2410 receives data from a remote WIT2410 device.
The command: ip 192.168.1.233 255.255.255.192 will set the SNAP’s IP address to 192.168.1.233 and will change the netmask to 255.255.255.192. The ip command without any parameters will display the current setting of the IP address and netmask. The SNAP includes a simple ping command that can be used to test the IP address and routing table settings. The SNAP can also obtain its IP address from a BOOTP server if one is present in the network.
the ethernet packets can not be transmitted in a timely manner, such as going through a router. Synchronization The SNAP uses broadcast or multicast datagrams for time synchronization. The default is for the master SNAP to broadcast datagrams to the 255.255.255.255 all-hosts IP broadcast address. Using the “sys xcast ”, SNAPs can be configured to use a more limited IP broadcast address, or a multicast address. All SNAPs in a network should be configured with the same “xcast” address.
PPP Operation The SNAP can be configured to operate as a PPP (Point-Point Protocol) server. PPP is a dial-in network connection that allows TCP/IP communication. A PPP connection allows a remote connected to a computer to be connected to network that the SNAP is on using the TCP/IP protocol. In order to operate the SNAP as a PPP server, the following sequence of commands must be entered. sys mode PPP save reset The SNAP will also allow the user to specify the starting IP address for the remotes that logon.
SNAP COMMAND SET The SNAP supports a series of commands that allow for configuring the Ethernet interface as well as the radio parameters of the on-board WIT2410. These commands can be entered during a telnet session or by using the WinSNAP24 utility when the SNAP> prompt is displayed. The commands are summarized here with detailed explanations following.
Size command. The xcast subcommand is used to set the multicast address to be used when the SNAP puts data out on the network. version Displays the SNAP firmware version.
SNAP Radio Commands Command hop [help length sequence [75|25] radio [A|B] [ help banner network cfg] remote [ help list send ] sync [help ether master override settings slave wire] Description Displays help screen for command Informs SNAP of radio hop dwell time Informs SNAP of number of frequencies in radio hop pattern Displays help screen for command Displays the banner of the specified radio Displays the network number (wn) of specified radio Enters radio command mode Displays he
remote This command lists the currently registered remotes by the serial number of the remote radio and the assigned handle. The send subcommand will send the specified data to the remote with handle specified in the command. This is intended as a debugging mode and not an operational mode. sync These commands set the operation of the synchronization signal used in multi-SNAP networks implementing seamless roaming.
PPP Mode Commands These commands are unique to the PPP mode. They are preceded by ppp.
base Sets base IP address for IP addresses to be assigned to remotes when in PPP server mode. The base address is assigned to the first remote that registers with the SNAP. The next remote to register is assigned the base IP address incremented by one. count Displays/sets the PPP base allocation count. This number must be equal or larger than the maximum number of remotes the radio as it determines the number of buffers the SNAP will set up to assemble SNAP datagrams.
RADIO MODEM CONFIGURATION The “radio” command provides access to several sub-commands that are useful in configuring the WIT2410(s) in the SNAP. The format for the radio commands is radio {A|B} [], where the {A|B} is either of the letters ‘A’ or ‘B’ used to specify to which radio the sub-command should be applied. The SNAP2410/2414 uses only radio ‘A’ and the SNAP2420 uses both radios ‘A’ and ‘B’. The command radio {A|B} banner can be used to display the banner from the radio.
default value of 90H corresponds to a duration of 10ms. The maximum value of FEH is 17.627ms. For best results do not specify a duration of less than 3ms. This value only needs to be changed in the master SNAP radio which broadcasts the parameter to all slave device radios. However, the SNAP command hop length must be used to set the new hop duration in the SNAP processor of each slave SNAP.
SNAP DATAGRAM PROTOCOL (SDP) Overview The SNAP Datagram Protocol (SDP) is a UDP (datagram) protocol implemented in the SNAP to communicate remote radio data to and from workstations on the network. The use of UDP datagrams permits the SNAP to unicast, multicast, or broadcast remote radio data to multiple workstations on the network. The SDP datagrams transmitted by the SNAP are sequenced so that a receiving workstation can detect datagrams that do not get delivered.
#define SDP_SNAP_MAGIC (0x73647030l) /* 'sdp0' */ #define SDP_USER_MAGIC (0x53445030l) /* 'SDP0' */ typedef unsigned char byte; typedef struct { ulong magic; byte seq; byte base_id[3]; } sdphdr_t; SDP Messages Each “message” that is contained within an SDP datagram consists of a type byte, a length byte, and some number of parameter bytes depending upon the type of the message. The values for the type byte are specified below.
SM_STARTUP message with a value of 2]. This allows the workstation software to become aware of remotes that are present in the network. This message will always be the first message in an SDP datagram. SDP_SM_CONNECT Byte(s) Value 0 Type = ‘c’ (0x63) 1 Length = 7 2-4 Unique-ID of remote radio 5 Receive sequence number for remote radio 6 Transmit sequence number for remote radio The SM_CONNECT message is transmitted by the SNAP when each remote radio connects to a base radio in the SNAP.
SDP_UM_STARTUP Byte 0 1 Value Type = ‘S’ (0x53) Length = 2 A workstation application will transmit this message (as a unicast, broadcast, or multicast) when it initializes, prompting the SNAPs on the network to send the current state of remote radios currently connected to each SNAP (i.e. an SM_STARTUP message followed by SM_CONNECT messages).
TROUBLESHOOTING Connect LED is not on. Check the power LED on the SNAP. Check the ethernet cable, making sure that it is fully connected. Check Cannot telnet to SNAP. Check the power LED on the SNAP. Check the ethernet cable, making sure that it is fully connected. Make sure the SNAP has a unique IP number on the network and one that is valid for the network, ie, that can be seen through switches, hubs and routers. Cannot communicate with a remote radio.
QUICK REFERENCE SNAP System Commands echo help reset save sys help outmax <1-212> mode [AP|PPP] xcast version Toggles user screen echo mode Displays command help screen Resets the SNAP to activate new parameters Stores current configuration in non-volatile memory Sets maximum transmit packet length Sets SNAP operating mode Sets SNAP multicast address Displays SNAP firmware version number Ethernet Commands arp -a -d -s ip password ping ro
Radio Commands dx ph pw wn [?|0-62] [?|0-fe] base only [?|0-35] base only [?|0-63] Sets range optimization in radio Sets hop duration in 69.
WIT2410 Command Summary Serial Commands sd[?|00..ff] sp[?|00..14] Set Data Rate Divisor Set Protocol Mode Network Commands wb[?|0|1] wd[?|1..3f] wn[?|00..3f] wg[?|0|1|2] wp[?|0|1] wr? dx[?|0..64] Set Transceiver Mode Set Default Handle Set Hopping Pattern Enable Global Network Modes Set Transmit Power Read Receive Signal Strength Set Range Optimization Protocol Commands pe[?|0..4] ph[?|00..fe] pl? pn[?|01..3e] pk[?|00..d4] pr[?|00..ff] pt[?|00..ff] pv[?|0|1] pw[?|00..
SPECIFICATIONS Radio Specifications Model Data Throughput Total over-the-air bandwidth Network Interface SNAP Network Topologies Repeater RF Output Power RF Modulation Frequency Range Operating Voltage Range Enclosure Dimensions Operating Temperature Licensing SNAP2410 230.4Kbps SNAP2420 460.8Kbps SNAP2414 230.4Kbps 460.8Kbps 921.6Kbps 460.
WARRANTY Seller warrants solely to Buyer that the goods delivered hereunder shall be free from defects in materials and workmanship, when given normal, proper and intended usage, for twelve (12) months from the date of delivery to Buyer. Seller agrees to repair or replace at its option and without cost to Buyer all defective goods sold hereunder, provided that Buyer has given Seller written notice of such warranty claim within such warranty period.
