Crystal Vision
General Purpose Interface
4 General Purpose Interface
Introduction
Each frame slot has up to six connections ‘a-f’ for GPI control and monitoring. These
connections are available at the rear of the frame on the 26-way D-Type remote connectors.
Safire 3 has six GPI inputs. Five recall one of 32 presets and the sixth is used to trigger an
auto transition of the Key Fade (see GPI Fade Keys control description).
Each General Purpose Interface (GPI) input is fitted with a 10kΩ resistor connected to the
in5V and in the following table, this equates to logic ‘H’. With the GPI preset recall
lines set to ‘level’ mode and no connections (logic ‘HHHHH’), preset 1 will be selected. With
the GPI preset recall lines set to ‘pulse’ mode, the GPI will be activated whenever a bit is
pulled low but no change to the preset selection will occur when all bits return to logic
‘HHHHH’. Note that preset 32 is not accessible in pulse mode.
Note
: Because the GPI inputs are sampled in the vertical interval it is recommended that in
‘pulse’ mode, the GPI should be asserted at least 2mS before the start of vertical sync to
ensure stability and held active for at least 40mS.
See
Presets, Resets & GPI/Os
in this manual for details of inverting the GPI preset logic.
Each General Purpose Interface output has a 270Ω resistor in seri
es with its output. This
allows for an external LED to be driven, connected to a DC voltage of +5V.
The GPI inputs can be programmed to automatically recall a previously saved preset
configuration. The 32 user preset configurations are selected using binary notation. Presets
33-40 are only accessible via VisionWeb or VisionPanel.
GPI
Low (<1V)
High (+5V)
1
‘a’ Recall preset bit 1
See following table for user preset control
2
‘b’
Recall preset bit 2
3
‘c’
Recall preset bit 4
4
‘d’
Recall preset bit 8
5
‘e’
Recall preset bit 16
6
‘f’
Fade Key Autotrans
Trigger Autotrans (see GPI Fade Keys Setup)
Table showing the six GPI functions
GPI
Bit 16
Bit 8
Bit 4
Bit 2
Bit 1
Preset
1
H
H
H
H
H
2
H
H
H
H
L
3
H
H
H
L
H
4
H
H
H
L
L
5
H
H
L
H
H
6
H
H
L
H
L
7
H
H
L
L
H
Safire 3 User Manual R1.3
11
24 March 2017
