Mitsubishi Electric GOT SIMPLE Series Operation Manual page 210

Communication error status
Communication error status of each port is displayed on this screen.
The following table describes the communication status that each display item shows.
Display item Status
NO ERROR No error
ERR Ovr. Overrun error
ERR Frm. Framing error
ERR Prt. Parity error
ERR Text Text error
TIME OUT Communication timeout
ERR Line Control line error
ERR Cmd. Command error
23 COMMUNICATION INTERFACE SETTING (COMMUNICATION SETTING)
208
23.4 Communication Monitor
Action
Communication is executed normally.
The receive data is sent continuously with a short interval.
Let the baud rate (communication speed) be equivalent between the GOT and counterpart equipment.
The communication frames of GOT and PLC are inconsistent.
Confirm the communication settings of GOT and PLC, such as data length, stop bit and baud rate.
The parity check conditions of GOT and PLC are inconsistent.
Let the parity check condition (odd or even) of GOT and PLC be consistent.
The sum data is inconsistent. Or the contents of the receive data are not consistent with the send command from
the GOT.
Let the communication settings and contents of data be consistent between the GOT and counterpart equipment.
(If NAK is received while the GOT is connected to the microcomputer board, a text error occurs.)
Though receiving is started, receive data is not sent.
Check the wiring between the GOT and its communication target.
(When the GOT is connected to the microcomputer board, confirm the terminator, CR, wiring, etc.)
The control line is not operating correctly.
Confirm the wiring of the control line.
A command contained in the receive data is not consistent with the send command from the GOT.