代码 20144: [Channel %1: ] Block %2 motion synchronous action: system variable access not possible

Parameters: %1 = Channel number %2 = Block number Definitions: When using system variables, it is assumed that a read/write operat ion can access the required data successfully. In accesses to encode r actual values or digital I/Os, the result depends on the availability of the corresponding hardware components. If an access within synchronized ac tions does not return a valid value, alarm 20144 is output. Outside synchr onized actions, such a read/write access causes block execution to be interrupted until the result is available. Block execution is subsequently continued. Reaction: NC Start disable in this channel. Interface signals are set. Alarm display. NC Stop on alarm. Remedy: Before reading/writing system variables, ensure that it is possible to acce ss the required hardware components. Program Continuation: Clear alarm with the RESET key. Restart part program