
B-62714EN/04 MAINTENANCE 2.LCD-MOUNT TYPE 16i/18i/21i-A/B
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2.2 LED INDICATIONS AND THEIR MEANINGS
On the I/O Link-II board, five green LEDs and one red LED are
provided for status indication. The locations and display information
of the LEDs are described below.
In the description below, each LED has one of the following states:
A : Turned off B : Turned on C : Blinking D : Irrelevant
LED 6 5 4 3 2 1
LEDs for state indication (green)
No. LED indication 1 2 3 4 Board state
1 B B B B State immediately after power-on
2 B B A A
The communication board is being
initialized.
3C D A A
DI/DO data transfer is being performed
normally.
4 A A A B
The communication board software is
running.
5 A A B B An F-bus error occurred.
6 A A B A An F-bus system emergency occurred.
7C D B A
A communication error (such as an FCS
error, command error, frame length error,
and response timeout) occurred. This
indication is provided if a communication
error occurs even once.
No. LED indication 5 Board state
1B
The I/O Link-II board is operating
normally.
LED for alarm indication (red)
No. LED indication 6 Board state
1 B A RAM parity error occurred.