LG GLOFA-GM Series User Manual page 322

Chapter 9 Diagnosis function
2) LED display in case LED display switch is pushed (Except for G6L-CUEB/G6L-CUEC)
If LED display switch is pushed during Loop-Back diagnosis, the result from comparison between the sent test
data and the received data through Loop-Back is displayed on LED. Cnet I/F module creates/sends test data in a
cycle of 1 sec. and checks the data if received exactly through Loop Back channel and then displays the result on
LED. If normal, all LEDs shall be OFF when LED display switch is pressed down. If abnormal in communication,
the number of errors per channel is displayed on LED display of LED No. 0~7 for the test result of RS-232C
channel and LED No. 8~15 for the test result of RS-422 channel. [Table 9.3] describes how to calculate the
number of errors on the basis of the displayed value on LED.
[Table 9.3] Error counter value when LED display switch is pushed
RS-232C error counter value (HEX)
LED # BIT value
0 D0
1 D1
2 D2
3 D3
4 D4
5 D5
6 D6
7 D7
(Example of calculation)
Remark
[Note1] If Cnet I/F module is normal and connection of Loop-Back Test is correctly applied, the number of errors
shall be '0', and if displaying button is pushed, all LEDs are to be OFF.
[Note2] Communication of the test data shall be as specified in Tx/Rx specification user has set.
Conversion method
Counter values calculated
by converting binary into
HEX regarding D0 as lower
bit, and D7 as upper bit.
Calculation of the number of errors when LED No.D0, D2 & D5 are turned ON.
2 + 2 + 2 = 1 + 4 + 64 = 69
0 2 5
Calculation of the number of errors when LED No D1, D5 & D7 are turned ON.
2 + 2 + 2 = 2 + 32 + 128 = 162
1 5 7
RS-422 error counter value (HEX)
LED # BIT value
8 D0
9 D1
10 D2
11 D3
12 D4
13 D5
14 D6
15 D7
9-5
Conversion method
Counter values calculated by
converting binary into HEX
regarding D0 as lower bit, and
D7 as upper bit.