On-board RS232-C Channels – CI853 Section 5 Maintenance
134 3BSE 027 941 R301
On-board RS232-C Channels – CI853
Table 26. On-board RS232-C Channels CI853 – Fault-Finding
Fault Possible Cause and Corrective Action
The PM8xx is transmitting and the
Tx1/Tx2 LEDs are flashing, but
the connected device is not
receiving data.
OR
The connected device is
transmitting, but the Rx1/Rx2
LEDs are not flashing.
• Check that the communication
interface cable is connected.
• Check the hand-shake signals.
The Tx/Rx signals are flashing
concurrently with
transmission, but the messages
are not being received correctly
by the connected device.
• Check that the baud rate, parity, and
number of data and stop bits are as
specified for the connected device.
• Check that the handshake procedures
are as specified at both ends.
• Check that the driver routines are
adequate, both in the controller and
the connected device.
• Disconnect power to the controller,
wait a moment and then power-up
again.
• Halt the program and initiate a reset
signal (INIT) from the PM8xx
processor unit.