Rs-232C Serial Communication Problem - Sam4s ER-390 Series Service Manual

8-7 RS-232C Serial Communication Problem

RS-232C Problem
Loop Back
Failure?
N
Communication
Failure?
N
H/W Handshake
Ok?
Y
End
SAM4S ER-390 SERIES
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1. Perform the "SELF TEST" in the S-MODE using the Loop
Back test Connector.
2. Check the connection of the RS-232C Connector and Loop
Y
Back Connector.
3. Check the TXD,RXD Pin on CPU.
4. Check the MAX232 Driving Chip and related Circuit on
Main Board.
Y
1. Check the connection of the RS-232C and Other side.
2. Check the I/F Cable whether it is open or short.
3. Check whether Signal is affected by the Cable Noise.
1. Check the connection of the H/W handshaking Line and Other
side.
N
2. Check the I/F Cable whether it is open or short.
3. Confirm the H/W handshaking Protocol.
8 Troubleshooting
8-7