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RL-ARM User's Guide (MDK v4)

RL-RTX RL-FlashFS RL-TCPnet TCP Socket Opening TCP Connection TCP Active Open TCP Passive Open Sending TCP Data Example for Sending Data Multiple TCP Connections UDP Socket Opening UDP Connection Sending UDP Data When DHCP Enabled When ARP Cache Empty Example for Sending Data IP Multicasting Multiple UDP Connections Configuring RL-TCPnet Static Configuration System Definitions Ethernet Network Interface PPP Network Interface SLIP Network Interface UDP Socket TCP Socket BSD Socket HTTP Server Telnet Server TFTP Server TFTP Client FTP Server FTP Client DNS Client SMTP Client SNMP Agent SNTP Client Error Function Runtime Configuration Library Files Using RL-TCPnet Stand Alone With RTX Kernel Event Driven Operation IP Address Assignment Ethernet Interface PPP Interface SLIP Interface Localhost Applications HTTP Server Script Language CGI Functions Ajax Support Using XML XML Example How it works SOAP Support SOAP Interface Large POST Messages Web Pages Default Page Error Pages Web on SD Card Web Update File System Interface Http Caching How it works Internal Web External Web Multi-user Authentication Using RAM File System FCARM File Converter PRINT Directive NOPRINT Directive PAGEWIDTH Directive PAGELENGTH Directive ROOT Directive Telnet Server Command Line Interface Multi-user Authentication Sending Reply Message Short Reply Long Reply Continuous Screen Update TFTP Server File System Interface TFTP Client File System Interface FTP Server File System Interface Multi-user Authentication Supported Commands FTP Client File System Interface SMTP Client SNMP Agent MIB Database MIB Interface MIB Entry MIB Table DNS Resolver Starting DNS Device Drivers Ethernet Driver Interrupt Mode Modem Driver Serial Driver Using Serial Link Cable Connection Modem Connection Windows Dial-up Add Direct Serial Link New Dial-up Connection Configure PPP Dial-up Configure SLIP Dial-up Debugging Enabling Debug Debug Level Redirecting Output Function Overview BSD Routines CGI Routines Ethernet Routines FTP Routines HTTP Routines IGMP Routines Miscellaneous Routines Modem Routines PPP Routines Serial Routines SLIP Routines SMTP Routines SNMP Routines System Functions TCP Routines Telnet Routines TFTP Routines UDP Routines RL-CAN RL-USB Example Programs Library Reference Appendix

Debug Level

The system is built from several modules that output debug messages. It is possible to configure the debug output for each module separately. There are three debug levels available:

Level Description
Off The debug messages for the selected module are disabled.
Errors Only Only error messages are output. This mode is useful for error tracking.
Full Debug In this mode, all debug messages are output. 

The following debug options are available:

  • Print Time Stamp switch enables or disables printing the time information with debug messages. If this switch is not enabled, the timing information is not printed.
  • Debug level for each module defines what kind of debug messages are printed.

The owner module of the displayed debug message is identified by the message prefix. The following system and application modules are configurable for debugging:

ID Module Description
MEM Dynamic Memory Management Allocates and releases frame buffers.
ETH Ethernet Protocol Handles ethernet link.
PPP Point to Point Protocol Handles serial line direct or modem connection PPP link.
SLIP Serial Line Internet Protocol Handles serial line direct or modem connection SLIP link.
ARP Address Resolution Protocol Handles ethernet MAC address resolution and caching.
IP Internet Protocol Processes the IP network layer.
ICMP Internet Control Message Protocol Processes ICMP messages. Best known example is the ping.
IGMP Internet Group Management Protocol Processes IGMP messages, Hosts groups and IP Multicasting.
UDP User Datagram Protocol Processes UDP frames.
TCP Transmission Control Protocol Processes TCP frames.
NBNS NetBIOS Name Service Maintains name access to your hardware.
DHCP Dynamic Host Configuration Protocol Handles automatic configuration of IP address, Net mask, Default Gateway, and Primary and Secondary DNS servers.
DNS Domain Name Service Handles the resolution of the IP address from a host name.
SNMP Simple Network Management Protocol Manages devices on IP network.
BSD Berkeley Socket Interface Processes TCP and UDP frames via standard BSD Sockets API.
HTTP Web server Delivers web pages on the request to web clients.
FTP FTP server Manages the files stored on the server and serves the file requests received from the clients.
FTPC FTP client Connects to FTP server to transfer files on the server, and to manage files stored on the server.
TNET Telnet server Allows remote clients to control the system using the command line interface.
TFTP TFTP server A simple service which allows to send files to or read files from the server.
TFTPC TFTP client Connects to TFTP server to send or receive files.
SMTP SMTP client Connects to SMTP server to send emails.

An example of the debug output is:

015.0 ETH:*** Processing frame ***
015.0 ETH: Dest.MAC: 1E:30:6C:A2:45:4E
015.0 ETH: Src. MAC: 00:11:43:A4:FE:40
015.0 ETH: Protocol: IP
015.0 ETH: Length  : 66 bytes
015.0 IP :*** Processing frame ***
015.0 IP : Src. IP :
015.0 IP : Dest.IP :
015.0 IP : Protocol: TCP
015.0 IP : Identif.: 0xBC73
015.0 IP : Length  : 52 bytes
015.0 IP : Frame valid, IP version 4 OK
015.0 TCP:*** Processing frame ***
015.0 TCP: Src. Port: 4568
015.0 TCP: Dest.Port: 80
015.0 TCP: Seq. Num.: 4132762560
015.0 TCP: Ack. Num.: 0
015.0 TCP: Flags    : SYN
015.0 TCP: Win. Size: 65535
015.0 TCP: Checksum : 0xEF81
015.0 TCP: Frame len: 32 bytes
015.0 TCP: Allocated Socket 2, port 80
015.0 TCP: Socket 2, State LISTEN
015.0 TCP: Process Options, 12 bytes
015.0 TCP: Remote MSS: 1460
015.0 TCP: Next state SYN_REC

In the above example, Ethernet, IP and TCP debug messages are enabled:

  • Received ethernet packets are processed by the Ethernet layer and a debug message containing Ethernet header information is printed out. Ethernet debug information contains source and destination MAC address, ethernet frame length and ethernet protocol type.
  • The packet is then passed to the IP layer. IP layer prints out IP debug messages containing the IP header information such as source and destination IP address, frame length, protocol type etc.
  • When the IP layer has processed the packet, the packet is passed to the upper TCP layer. TCP layer prints out TCP debug messages containing the TCP header information such as source and destination ports, sequence and acknowledge numbers, checksum value, frame length etc.
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