Error Status Indication; Eerrors Caused By Midi Loop; Clock Pulses Duration; Dac Calibration Procedure - Roland SH101-M Owner's Manual

SH101-M
APPENDIX B. - ERROR STATUS INDICATION
If any fatal error occurs during the interface operation, the interface disconnects itself from
instrument's circuits ant stops the MIDI communication. However, the instrument still can be controlled
by its own keyboard, panel knobs and switches.
The error status is indicated by blinking indication LED (green blinking). The number of LED
blinks is indicating the error type:
(A): 1x error in MIDI communication with host system (e.g. input or output MIDI data buffer
overflow).
(B): 2x error in internal communication between interface's CPU and peripheral circuits,
Error (A) can be solved automatically if "Auto Reset" system parameter is set "On" (see chapter
4.1.4). In that case the interface returns automatically to basic stand-by mode.
Error (B) is fatal. If this error occurs, the interface must be reset to restore the operation. It is
necessary to turn the SH-101 instrument off and on after a while.
APPENDIX C. – ERRORS CAUSED BY MIDI LOOP
When SH101-M interface is controlled by a sequencer (HW or SW) and the devices are
connected bi-directionally (with both MIDI cables) and the sequencer isn't set correctly, communication
loop might occur and the entire MIDI system "freezes". It is caused that all MIDI data incoming from
sequencer to interface's input are transferred to interface's output (THRU function) and back to the
sequencer. This causes infinite cyclic transfer of the same MIDI data.
To avoid this situation, throughput of MIDI data from input to output must be turned off in the
DAW / Sequencer. This function is usually called MIDI ECHO or MIDI THRU. Check the user manual
of your DAW / Sequencer.
APPENDIX D. – CLOCK PULSES DURATION
Duration of generated clock pulses (controlled by system parameter Clk Pulse Length) need not
be changed from the factory pre-defined setting in most cases. Only if the instrument reacts unreliable
(i.e. some pulses are omitted and the sequencer and arpeggiator run irregularly) it is necessary to
adjust the duration of the clock pulses (set the longer duration).
APPENDIX E. – DAC CALIBRATION PROCEDURE
If an exactly same tuning of the instrument keyboard and master MIDI keyboard is required, D/A
converter controlling VCO of the instrument must be calibrated. The calibration range is approx. ±90
cents, calibration step is 1,465 cent (see table 5).The calibration constant is stored in interface memory
so the new value remains unchanged after the instrument is switched off. The value of the calibration
constant is set to 64 ( ± 0 cent, no shift) ex-factory.
Remarks:
1
) Calibration procedure is not necessary if keyboard DAC and VCO of the SH-101 are adjusted
exactly as described in service manual of the instrument.
2
) The calibration eliminates only shift of instrument's control voltage! Wrong range and non-linearity
of CV cannot be removed.
Calibration procedure consists in adjusting of "CV Calibration" constant (stored in the interface's
memory). This procedure is executed via MIDI System Exclusive Message:
F0 00 20 21 ii 5C 30 05 dd xx F7 [hex]
where "ii" is Device ID byte, "dd" is databyte and "xx" is checksum. The "dd" databyte contents the
calibration constant depending on required fine tuning as shown in table 2.
No part of this publication may be reproduced in any form without the written permission of CHD Elektroservis.
MIDI Interface for Roland SH-101
Copyright © 2017 CHD Elektroservis. All rights reserved.
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Model 8-438 ver. 1.0