Crystal Vision
Hardware installation
CoCo104 User Manual R2.0
9
26/09/05
2.3 Using module GPIs
Each slot has an associated set of GPI connections for remote control and external status
outputs on the frame rear-panel remote connectors. For convenience, GPI lines are
associated with reference codes ‘a’ to ‘f’ in the connector pin-out tables for each frame.
GPI lines can be used for either remote preset control or a second serial port for the CoCo
Controller panel. GPI lines ‘e’ and ‘f’ are reserved for an optional remote fader.
To enable GPI preset selection, ensure that the four jumpers J1, J4, J16 and J17 are all
positioned
away
from the edge connector.
The following table shows the binary weighted code required to recall presets 1 to 16
according to the state of GPI ‘e’. A ‘0’ is an open GPI input and a ‘1’ is a grounded GPI
input.
Recall Preset
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
GPI ‘a’
0 1 0 1 0 1 0 1 0 1
0
1
0
1
0
1
GPI ‘b’
0 0 1 1 0 0 1 1 0 0
1
1
0
0
1
1
GPI ‘c’
0 0 0 0 1 1 1 1 0 0
0
0
1
1
1
1
GPI ‘d’
0 0 0 0 0 0 0 0 1 1
1
1
1
1
1
1
OPEN (+5V)
GROUND
‘a’, ‘b’, ‘c’, ‘d’
See table above
‘e’
No action
IN/FADER/OUT – depends on JP7
‘f’
No action
IN/POWER/OUT – depends on JP7
GPI input assignment
GPI input connections have 10k
Ω
pull-up resistors to +5V. Closed-contact switches or
+5V to +24V logic levels can be used
GPI output connections (when provided) have 330
Ω
series resistors fitted to drive LEDs
and 10k
Ω
pull-up to +5V (to drive a remote input).
Note:
Jumpers PL 1, 4, 16 and 17 should be left in the left hand GPI position to enable normal
GPI operation and in the right hand position to enable RS485 comms for a CoCo
Controller.
