| 摘要 |
A programmed controller controls a machine or process by emulating state diagrams and executing an applications program having a number of blocks of statements each block corresponding to a step in the operation of the machine or process, each state diagram being represented by a program loop. Each loop has only one state active at any one time and has variables such as pointers in each of which is stored the address of an active block. When transition conditions of a state in a block are satisfied, a decision point is reached, that state is deactivated and another state activated in a desired sequence with consequent required operation of the machine or process. The transitions that occur with regard to which states are active and the order in which they occur are recorded and later retrieved and presented for example for debugging uses to a user. |
