IEC 63035:2017 pdf download

IEC 63035:2017 pdf download.MIDI (musical instrument digital interface) specification 1.0 (Abridged Edition, 2015)
1 Scope
This International Standard specifies a hardware and software specification which makes it possible to exchange symbolic music and control information between different musical instruments or other devices such as sequencers, computers, lighting controllers, mixers, etc. using MIDI technology (musical instrument digital interface).
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 601 30-9, Connectors for frequencies below 3 MHz – Part 9: Circular connectors for radio and associated sound equipment
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: • IEC Electropedia: available at http://www.electropedia.org/ • ISO Online browsing platform: available at http://www.iso.org/obp 3.1 velocity parameter which typically changes the intensity and resultant volume of the note that is being played and varies according to the force applied Note 1 to entry: Velocity is used as Key Velocity as in a piano key. 3.2 aftertouch parameter that measures the level of intensity applied to a note after it has been played and continues to be depressed Note 1 to entry: Typically, Aftertouch is useful for adding vibrato or tremolo effects to a sound in much the same way that a violin can add volume or pitch changes to a sustained note using finger vibrato or additional bowing intensity. 3.3 modulation wheel wheel controller found on synthesizers that players can use to progressively introduce modulation depth to a sound 3.4 pitch wheel wheel type device, normally found to the left of a synthesizer keyboard, used to manipulate the pitch of a played note or notes 3.5 pitch bend activity or message, generally initiated by a pitch wheel, that smoothly raises and/or lowers the pitch of note or chord 3.6 oscillator circuitry or software program that generates the kernel of a synthesizer sound Note 1 to entry: In the early days, oscillators generated fairly basic sound types (sawtooth, square, pulse etc). In modern synthesizer engines, oscillators can be driven by myriad waveforms and samples. 3.7 pan parameter that specifies the location of a sound within the stereo field
4 General
4.1 Hardware The hardware MIDI interface operates at 31 ,25 × (1 ± 1 %) kBd asynchronous, with a start bit, 8 data bits (D0 to D7), and a stop bit. This makes a total of 1 0 bits for a period of 320 µs per serial byte. The start bit is a logical 0 (current on) and the stop bit is a logical 1 (current off). Bytes are sent LSB first. Circuit: (See Figure 1 ). 5 mA current loop type. Logical 0 is current ON. One output shall drive one and only one input. To avoid ground loops, and subsequent data errors, the transmitter circuitry and receiver circuitry are internally separated by an opto-isolator (a light emitting diode and a photo sensor which share a single, sealed package). The receiver shall require less than 5 mA to turn on. Rise and fall times should be less than 2 µs.Connectors: DIN 5 pin (1 80°) female panel mount receptacle which is specified in IEC 601 30-9 as type designation IEC-04. The connectors shall be labelled “MIDI IN” and “MIDI OUT”. Note that pins 1 and 3 are not used, and should be left unconnected in the receiver and transmitter. Pin 2 of the MIDI In connector should also be left unconnected. The grounding shield connector on the MIDI jacks should not be connected to any circuit or chassis ground. When MIDI Thru information is obtained from a MIDI In signal, transmission may occasionally be performed incorrectly due to signal degradation (caused by the response time of the opto- isolator) between the rising and falling edges of the square wave. These timing errors will tend to add up in the “wrong direction” as more devices are chained between MIDI Thru and MIDI In jacks. The result is that, regardless of circuit quality, there is a limit to the number of devices which can be chained (series-connected) in this fashion.