Listen AmpConnect621, User Manual

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AmpConnect 621
™
Manual Digital I/O Operation 31
Digital I/O Read Examples
The Digital I/O input of AmpConnect 621 can read the state of external TTL voltage levels and switch
closures in a SoundCheck test sequence.
When set to Read (Input), the selected Bit(s) are pulled high through an internal 100K resistor.

+3.3 VDC is present at all enabled Bit lines that are set High in the Message Step (switch on)

You may want to use external pull-up resistors to increase noise immunity or pull-down resistors to
force the input low, as shown in
Figure 7-8 .
Bit 4 Pulled Low - Normally Open Switch

In Figure 7-8 a Normally Open switch is wired across Bit 4
and +5 VDC

A 2.2 k Ω resistor is also wired from Bit 4 to Ret. (GND)

When the switch is open, the Bit 4 physical line will be
pulled
Low through the 2.2 k
Ω
resistor

When the switch is closed, Bit 4 will go High when
+3.3 VDC is applied
When the Digital I/O Message Step in Figure 7-9 is executed in
the sequence, it will Read the state of the physical input and
compare it to the setting of Bit 4.

Bit 4 is set Low as the “normal” mode for the step so that it
will react to the Bit being pulled high by the external switch
closure

The Pass/Fail radio buttons are not used

If the actual state of the input agrees with the setting for Bit
4 the step will issue a "PASS" verdict

If the actual state disagrees the step will issue a "FAIL"
verdict. This “FAIL” will be used in the Step Configuration
shown in
Figure 7-10 .

Right click on a step in the Sequence Editor to select
“Configure Step”

In this case, the “FAIL” verdict is used to tell the step to jump
to a message, “Bit 4 Switch Closure”.
This might be used to stop the sequence and let the line
operator know that a problem has occurred.

See Step Configuration in the main SoundCheck Manual
for more information on uses of Conditional Branching
Digital I/O Port
Bit 0
Bit 1
Bit 2
Bit 3
Bit 4
Bit 5
Bit 6
Bit 7
+3.3V
Ret. (GND)
2.2k Ohm
External Switch
(Normally Open)
Figure 7-8: Bit 4 Pulled Low
Figure 7-9: Bit 4 Set Low
Figure 7-10: Jump On Fail