1C31166G01 Lift Logic Control

1C31166G01 operation adopts the cycle scanning mechanism, thus using the usual method of table checking, the instruction time interval of each table checking is too long to meet the accuracy requirements of the given curve. During PLC operation, the information exchange between its CPU and each device, the execution of user programs, signal acquisition, output of control quantities and other operations are carried out in a cycle scanning manner according to a fixed order, and all functions are queried, judged and operated in each cycle.

1C31166G01 Usually, in one scanning cycle, the work of six steps is basically completed, including operation monitoring, exchanging information with the programmer, exchanging information with the digital processor, exchanging information with the communication processor, and executing the user programme and input/output interface services. In one cycle, the CPU executes the entire user programme only once. This mechanism has its convenient side, but the real-time performance is poor. Excessively long scanning time directly affects the effect of the system response to the signal. Under the premise of guaranteeing the control function, minimising the cycle scanning time of the CPU is a very complex issue.

1C31166G01 can only take the method from the shortest execution time of the user programme. The programme scanning time of the logic control section of the lift has exceeded 10ms, and despite the adoption of some methods to reduce the programme scanning time, it is still impossible to reduce the scanning time to less than 10ms. At the same time, the braking section curve adopts the principle by distance, and the response time of each distance to should not be more than 10ms. in order to meet the real-time requirements of the system, the interrupt method is adopted in the way of generating the speed curve, thus effectively overcoming the limitations of PLC scanning mechanism.