Alcorn Mcbride AM-4, Hardware And Software Reference Manual

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12 Controlling the AM-4
Controlling the AM-4
Parallel Control
Parallel Inputs
Be sure to configure the
DIP switch before
connecting any wires.
The AM-4 Digital Audio Machine can be controlled using either contact closures or
voltage inputs on the female DB-37 Control Connector. DIP switch number 1 selects
between the two input types. Voltage inputs are rated for 24 VDC. The table below
describes the function of each input.
Function Voltage
Input
Pins Contact
Closure
Pins Description
Mute 11(+),1(-) 1,20 Ramps the audio to zero volume and
maintains it there as long as Mute is
asserted. When Mute is released, audio
returns to full volume.
Pause 12(+),2(-) 2,21 Pauses the file currently playing. Pause is
maintained as long as it is asserted. Play
will resume when the file is commanded to
play again.
Stop 13(+),3(-) 3,22 Stops the file currently playing. If the file
is a Play List, it is aborted.
Loop 14(+),4(-) 4,23 Causes the selected file to loop indefinitely
from beginning to end. If the file is a Play
List, all tracks will be played and then the
file will loop. The state of this input is
examined at the
start of each file.
File Select 1 15(+),5(-) 5,24 Binary-encoded input plays files 1-15.
File Select 2 16(+),6(-) 6,25 Binary-encoded input plays files 1-15.
File Select 4 17(+),7(-) 7,26 Binary-encoded input plays files 1-15.
File Select 8 18(+),8(-) 8,27 Binary-encoded input plays files 1-15.
The binary file select inputs are used to play the first 15 files. These inputs may be
contact closures or voltages, depending upon the input select DIP switch described in
the Configuration DIP switch section of this manual. The inputs are change-sensitive;
that is, when a change is detected, the new file will be played. It is therefore
important that the four bits change at the same time.
If the same file number is selected repeatedly it will normally interrupt itself and
begin again. When processing a Play List, if the Play List is selected repeatedly it
advances from entry to entry within the list – unless the “Uninterruptible” flag has
been set (see the Play List section for more information).