I worked as a contractor for Microsol where my work included the design and implementation of the ABB SPAbus and Modicon Master Modbus protocols for real time industrial control processing applications. These protocol implementations were flexible allowing the downloading of user configurable hardware port parameters and poll and data map tables. The protocols were required to be compatible with the Microsol XCell 68020 development environment and this involved the solving of a variety of design issues such as concurrent database access and the propagation of database data to other networked 68020 processors.
From a practical perspective, development tools used included the Borland C PC development environment, the Microtec C to 68000 cross compiler and the Microtec 68000 debugger. Communications skills gained included the use of protocol analysers, RS232/RS485 cabling and optical fibres. Hardware skills gained included the extensive use of industrial relays, EEPROM blowers and a familiarity with Microsol's own proprietary 68020 processor boards.
The Modbus protocol work was priced for the job and I went through the complete lifecycle from agreeing requirements to passing acceptance testing.