Early teletypewriters used the ITA-1 Baudot code, a five-bit code. Early teleprinters used the Baudot code, a five-bit sequential binary code. A feature of the Baudot code, and subsequent telegraph codes, was that, unlike Morse code, every character has a code of the same length making it more machine friendly. The Baudot code was used on the earliest ticker tape machines (Calahan, 1867), a system for mass distributing information on current price of publicly listed companies. These served for switching the electric current. Current flowing through transmission lines induces a magnetic field that surrounds the lines of each phase and affects the inductance of the surrounding conductors of other phases. A 15 kV transmission line, approximately 175 km long, connected Lauffen on the Neckar and Frankfurt. The economic advantage of doing this is greatest on long, busy routes where the cost of the extra step of preparing the tape is outweighed by the cost of providing more telegraph lines.

A heliograph is a telegraph that transmits messages by flashing sunlight with a mirror, usually using Morse code. The world's first permanent railway telegraph was completed in July 1839 between London Paddington and West Drayton on the Great Western Railway with an electric telegraph using a four-needle system. Entry to and exit from the block was to be authorised by electric telegraph and signalled by the line-side semaphore signals, so that only a single train could occupy the rails. In a punched-tape system, the message is first typed onto punched tape using the code of the telegraph system-Morse code for instance. In a test of the system, a message was relayed 640 km (400 mi) in four hours. It is then, either immediately or at some later time, run through a transmission machine which sends the message to the telegraph network. A teleprinter is a telegraph machine that can send messages from a typewriter-like keyboard and print incoming messages in readable text with no need for the operators to be trained in the telegraph code used on the line. The first machine to use punched tape was Bain's teleprinter (Bain, 1843), but the system saw only limited use. A solution presented itself with gutta-percha, a natural rubber from the Palaquium gutta tree, after William Montgomerie sent samples to London from Singapore in 1843. The new material was tested by Michael Faraday and in 1845 Wheatstone suggested that it should be used on the cable planned between Dover and Calais by John Watkins Brett.

The advantage of doing this is that messages can be sent at a steady, fast rate making maximum use of the available telegraph lines. Also, it is difficult for a merchant transmission line to compete when the alternative transmission lines are subsidized by utilities with a monopolized and regulated rate base. In this system each line of railway was divided into sections or blocks of varying length. The idea was proved viable when the South Eastern Railway company successfully tested a three-kilometre (two-mile) gutta-percha insulated cable with telegraph messages to a ship off the coast of Folkestone. Morse, fascinated by the idea. The idea for a telegraph of this type was first proposed as a modification of surveying equipment (Gauss, 1821). Various uses of mirrors were made for communication in the following years, mostly for military purposes, but the first device to become widely used was a heliograph with a moveable mirror (Mance, 1869). The system was used by the French during the 1870-71 siege of Paris, with night-time signalling using kerosene lamps as the source of light. As first implemented in 1844 each station had as many needles as there were stations on the line, giving a complete picture of the traffic.

The heliograph was ideal for use in the American Southwest due to its clear air and mountainous terrain on which stations could be located. In Cooke's original system, what are electric cables a single-needle telegraph was adapted to indicate just two messages: "Line Clear" and "Line Blocked". As lines expanded, a sequence of pairs of single-needle instruments were adopted, one pair for each block in each direction. However, any such breaker sold today does have one flaw. A worldwide communication network meant that telegraph cables would have to be laid across oceans. Is using extension cables to charge an EV safe? On land cables could be run uninsulated suspended from poles. Multiple messages can be sequentially recorded on the same run of tape. Historically, transmission and distribution lines were often owned by the same company, but starting in the 1990s, many countries liberalized the regulation of the electricity market in ways that led to separate companies handling transmission and distribution. The insurance provider says it is the same sort of scenario as a customer putting the wrong fuel in their internal combustion engine car, with insurers covering these claims as accidental damage also. Australian forces used the heliograph as late as 1942 in the Western Desert Campaign of World War II.