The paper deals with a unified environment for the design and implementation of control schemes. The widely used MATLAB-SIMULINK is used for control scheme description. The implementation hardware is from Mitsubishi PLC. The SIMULINK library was extended with target hardware blocks. After an off-line design procedure, which can be combined with hardware-in-the-loop experiments, the control scheme is translated into PLC code in three steps. The results show that the autocoding of small, low-cost industrial controllers can be efficiently realized by integrating widely used, inexpensive and commercially available tools. © 1998 Elsevier Science B.V. All rights reserved.