Yamaha 01x, Service Manual

Page: 75 / 153

75
O1X
4.14 mLAN function check .....
(14) mLAN
(1) Outline
The connection function between the DM circuit board and
MLN2 circuit board is checked. Specifically, the following 5
items are checked automatically.
●
Audio signal system check
The audio signals flow in the loop of DSP7 -> MLN2 circuit
board -> External PC -> MLN2 circuit board -> DSP7. The
values of all 24Out and 24In are compared to check for
correct signal flow.
●
Word clock frequency and lock check
The MLAN LOCK signal is monitored to check if they are
locked. Also, the frequency counter in PLLP2 measures the
word clock frequency and check that it is 48/96KHz.
●
Word clock control and synchronous detection check
Change the word clock source of this unit set in "EXT-
mLAN" (external PC) to "INT: 44.1kHz" (Internal 44.1KHz)
to check that synchronization is cancelled. Next, set the word
clock source back to "EXT-mLAn" (external PC) again to
check that synchronization is provided.
●
MLAN M/S-IN • S-OUT check
The MLAN M/S-OUT flag is inverted on the PC side and
inputted to the MLAN M/S-IN terminal of CPU. The S-
OUT and S-IN flags are compared to check if they are
correct.
●
MIDI check
There are 5 systems of MIDI internally. As 2 systems (MIDI-
A and B terminals) among them are not via CPU, they cannot
be checked automatically. Following 3 systems are checked
here.
SCI0 (CPU TXD0, RXD0)<--->MLAN MIDI4
SCI1 (CPU TXD1, RXD1)<--->MLAN MIDI5
SCI2 (CPU TXD2, RXD2)<--->MLAN MIDI1
When the MIDI signals output from TXD[0-2] flow through
the PC and back to RXD[0-2], their values are compared to
check if they are correct. The waiting time since the signal
is output from TXD[0-2] until they reach RXD[0-2] and
checked is 100msec.
(2) Execution method in the normal state
It is necessary to make settings for this test on the PC to be
connected to O1X (MLN2 P.C.B.) and application software for
testing in advance. (See Item 2.)
The loop-back test item should be executed for both [mLAN 1]
terminal and [mLAN2] terminal.
1
Connect the IEEE1394 cable to the [mLAN 1] terminal.
2
Execute "Start_mLanTester_for_Service .vbs" in
mLANTester.
3
Before executing the mLAN test, execute the USER
DATA "Backup".
Save the following user data.
1) Word clock setting
2) Audio channel number, number of channels
3) MIDI channel number
4
After executing the user data backup, turn on the power while
pressing the [UTILITY] and [AUDIO] switches of the 01X
once again.
5
Select "14:mLAN" by turning [KNOB-1] of the O1X.
6
Press [KNOB-8] of the O1X.
7
LED lighting test
7-1) Click on "Function List".
7-2) Click on "LED".
7-3) Click on "START" and check that the ACTIVE LED
(LD4) flashes.
7-4) Click on "STOP".
7-5) Click on "CLOSE".
8
Loop-back test
<48kHz test>
8-1) Click on Loopback "B".
8-2) Click on "Start", and "Executing" will be displayed.
Application settings will be as follows.
• FS=48kHz
• Word clock internal
• The 24In audio signal is output as it is to 24Out.
• The 5IN MIDI signal is output to 5Out.
• The S-IN signal is inverted and output to S-OUT.
8-3) check that "Auttest O.K." is displayed.
8-4) Click on "Stop".
The following message appears while the DIAG test
is being executed.
14:mLAN
mLAN TEST NOW...
PC
O1X