1, Mitsubishi PLC programming cable communications port and baud rate are set correctly. Such as: Point Serial Icon -> port RS232-> baud 9.6k/bps-> OK -> then click communications test, if successful, displays the communication hardware connection is no problem.
2, Mitsubishi PLC Are there written procedures, or that the PLC is worked properly.
3, the program is encrypted, the program also lost.
4, Mitsubishi PLC whether damage.