Omron Programmable Terminals NT31 NT31C Setup Manual page 250

Responding to Displayed Error Messages
Probable Causes and
Remedies
Error Details
Parity Error
Framing Error
Over-run Error Over-run Error
FCS (Check Sum) Error
240
Example:
Parity error at serial port A
Receive Errors
The following errors can occur when receiving data.
• Parity error
• Framing error
• Overrun error
• FCS (sum value) error
• Time out error
• Data over flow error
• PC unit No. error (host link only)
• NAK received (in the case of the host link, the end code is also displayed)
• Undefined command error
Send Errors
The following errors can occur when receiving data.
• Time out error
• Data over flow error
The remedies to take in accordance with the displayed cause are indicated in the
table below.
Displayed Probable Cause
Communication parameters/
conditions set incorrectly.
The connecting cables are not
connected correctly.
Noise caused data corruption during
communication.
Noise caused data corruption during
communication.
The PC is transmitting incorrect
data.
Remedy
Check if the settings at the host for parity bit, frame
length, communications speed, stop bit length and
flow control agree with those at the NT31/NT31C.
Check the communication cable connection and
perform a conductivity test. If there is a fault,
replace the cable. For details on communication
cables, refer to Section 4 Connecting to the Host
from the RS-232C Port, and Section 5 Connecting
to the Host from the RS-422A/485 Port.
Carry out grounding work in accordance with the
conditions by referring to 3-1-4 Grounding, page 34.
Carry out grounding work in accordance with the
conditions by referring to 3-1-4 Grounding, page 34.
Check the operation at the host side.
Section 7-2