Micro-Robotics: TCP/IP Networking with the VM-1 Embedded Controller

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Networking with the VM-1

The VM-1 has a TCP/IP stack built into its programming language. It also has drivers for other networks, such as CAN, I2C, etc.

The TCP/IP protocols enable it to communicate with other computers or controllers, over the Internet, or via local area networks (LAN). Because they are open standards and the basis of the Internet, many existing applications already use these protocols. The VM-1 can:

Connect to an Ethernet LAN
Connect via GPRS (the Internet over a mobile phone network)
Make dialup connections through a modem
Send email (e.g. data logging and reporting)
Receive email
Serve web pages to any web browser, which can then both display data and remotely control the VM-1 and attached systems
Transfer files by FTP (File Transfer Protocol) either as client or server
Synchronize the time and date to Internet time servers

Extra Hardware

For dialup and GPRS communication a VM-1 serial port can be connected to a modem or GPRS terminal.

For Local Area Network (LAN) operation an Ethernet interface is available as a separate module or built in to custom designs.

Venom Language Support

All networking is handled by the Protocol object built into the Venom-SC language on every VM-1 controller. Protocol makes either direct or implicit use of the following protocols:

PPP

Point to Point Protocol: connection to an Internet Services provider, by modem or by GPRS terminal, using the VM-1's serial line. Our PPP stack handles:

PAP or CHAP authentication
link negotiation
Automatic assignment of an IP address
Automatic assignment of DNS server
Host mode for connecting to Windows dialup networking or similar

ETH

The Ethernet Protocol object sets up an interface for sending and receiving IP packets through Ethernet hardware. Support includes routing packets through a LAN gateway to other networks and completely automatic ARP (MAC - IP address resolution).

TCP

Transmission Control Protocol : A raw TCP service providing a reliable bi-directional connection for sending and receiving streams of character data using any protocol (i.e. compatible with simple serial data).

Telnet

A simple Telnet service.

IP

The IP module includes routing, assignment of a local IP address to outgoing packets and built-in loopback interface on the standard loopback address 127.0.0.1 to simplify testing.
The IP object also includes a utility for converting IP adresses between 'dotted quad' strings like "129.168.27.41" and a simple 32 bit integer value.

ICMP

The standard ICMP echo service, better known as 'ping', is supported. A VM-1 responds to 'ping' requests and can measure the response time after sending a ping request to another network host.

UDP

User Datagram Protocol: a datagram service for times where the overheads of repeatedly opening and closing a TCP connection would be excessive, such as:

Rapid real time updates of continuously varying data
Simple query/reply services such as DNS and time/date
Individual control events such as switching a remote device on and off
Applications that require broadcasting a message simultaneously to every node on a LAN

DNS

Our automatic cached DNS converts domain names to IP addresses and saves time by remembering recent lookups

Time

A clock calendar synchronised to GMT time servers on the Internet, providing time and date information indendently of the VM-1's optional real time clock hardware. This is used e.g. for date-stamping outgoing email (see below)

SMTP

Simple Mail Transfer Protocol for sending email: our SMTP client enables your Venom program to send email messages anywhere in the world.

POP3

Post Office Protocol version 3: collects mail from an ISP's mailbox so that you can send an email message to the VM-1. Typical uses might be to send coded commands, or to request data to be sent back by reply email.

HTTP

The HTTP Protocol object enables the VM-1 to run a web server so that a system can be remotely monitored and controlled with any commonly available web browser. Full details on the HTTP page.

FTP

The VM-1 supports File Transfer Protocol as both client and server.

Documentation

The Venom Networking guide is now part of the Venom documentation available in either Windows Help or PDF file formats - see Software Manuals page.

The Networking guide includes some simple example applications that can be copied and pasted into your program editor and adapted for your own purposes.

Embedded Controller TCP/IP Networking