Cause:
- When a load signal is given in external mode, the path of the program to load has not been configured;
- When a run signal is given in external mode, no program is loaded.
Troubleshooting:
For cause 1, check whether a default program path or program paths for programs 1-4 have been configured on the system signal configuration screen and the corresponding signals have been supplied.
For cause 2, check whether a program is loaded when the run signal is supplied.
Solution:
For cause 1, configure the path of the program to load first, then issue the load signal.
*** ***For cause 2, issue the load signal first, then the run signal.
Case sharing:
On the system signal configuration screen, leave the program paths for the default program and programs 1-4 unconfigured, then give a load signal in external mode; error 503 will be reported.