Casio CE-T300, Service Manual

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12) RS232 port check
This test will check the RS232 port. Connect the loop back connector before operate this
check.
Operation : X 2 m 7 #2 Key
m: 0= One time loop check
1= Loop check continuously
2= One time loop check (Ignore the CD,CI signals. Only COM1 port)
3= Loop check continuously (Ignore the CD,CI signals. Only COM1 port)
X: 0= COM1
Test details
1) Check of the control shignals (CTS,DSR,RTS,DTR,CD,CI) Low/High level.
2) Sending data (0A5h) from Txd line and receiving data from Rxd line.
[PRINT] [DISPLAY]
LOOP BACK CONNECTOR (D-SUB9pin Female)
COM1
TxD
RxD
CTS
RTS
DTR
DSR
CD
CI
3pin
2pin
8pin
7pin
4pin
6pin
1pin
9pin
NOTE: Error code is as follows:
01= Framing error 02= Over run error 04= Parity error
40= Data error (Not 55) 80=Time out error