Troubleshooting

FP2−CCU

5.1Operation if an Error Occurs

5.1.2If the ERROR LED on the Computer Communication Unit Lights

What the ERROR LED does

The ERROR LED on the Computer Communication Unit lights there is a problem with communication between the unit and the external device. There are two ERROR LEDs, ERR1 and ERR2, for each channel.

CCU

ERROR LED

CCU

SDRDERRSD RD ERRALARM

COM.1COM.2

Operation of the unit continues even if the ERROR LED lights.

If an error occurs during reception, the frame currently being received is cleared, and the ERROR LED lights. If the next frame is received normally, however, that frame is processed as a received frame, and the ERROR LED goes out.

CPU unit operation when the ERROR LED lights

Operation of the CPU unit is not affected.

Tip

−In some cases, the contents of the error that occurred may be returned to the host side, such as a computer or display panel, as an error re- sponse.

−No response is returned if the transmission speed (baud rate) or char- acter bit is different between the two devices.

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