Crystal Vision Hardware installation
Smart Switch 3G User Manual R1.10 701/09/2016
2.3 General Purpose Interface (GPI)
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.
GPI
Low (<1V) High (+5V) Notes
1 ‘a’ See configuration table Held low for tally
2 ‘b’ Held low for tally
3 ‘c’ See configuration table Held low for tally
4 ‘d’ Held low for tally
5 ‘e’ Alarm condition Non-alarm See alarm table
6 ‘f’ See alarm table
As supplied, each GPI output has a 270Ω resistor in series with its output. This allows for an
external LED to be driven, connected to a DC voltage of +5V.
The GPI inputs can be used to control input selection/routing and are configurable for either
pulse or level trigged. They can also be used to give a tally of the selection/routing. When GPI
control is selected to ‘level’ GPI = High (floating) selects Input 1 and GPI = Low (pulled to
ground) selects Input 2.
The following GPI modes can be selected using Statesman, active front panel or board edge
control:
label
edge label
No control,
tally only No GPI Tally on b No GPI control. Tally on GPI 'b' for Output 1 routing and 'd' for
Output 2 routing
Level, 1 GPI Level a Tally b Level control on GPI 'a' for Output 1 routing and 'c' for Output 2
routing. Tally on GPI 'b' for Output 1 routing and 'd' for Output 2
routing
Pulse, 1 GPI Edge a Tally b Pulse (edge) control on GPI 'a' for Output 1 routing and 'c' for
Output 2 routing. Tally on GPI 'b' for Output 1 routing and 'd' for
Output 2 routing
Pulse, 2 GPI Edge ab Tally ab
Pulse (edge) control on GPI 'a' & 'b' for Output 1 routing and 'c' &
'd' for Output 2 routing. Tally on 'a' & 'b' for Output 1 routing and
'c' & 'd' for Output 2 routing
Pulse, 2 GPI,
no tally Edge ab No Tally
Pulse (edge) control on GPI 'a' & 'b' for Output 1 routing and 'c' &
'd' for Output 2 routing. No tally
Pulse, 2 GPI,
force GPI Force Pulse (edge) control on GPI 'a' & 'b' for Output 1 routing. Tally
on 'a' & 'b' for Output 1 routing. GPI 'c' when held low enables
"force" mode so that GPI 'a' & 'b' switch to other input, even if a
fault condition exists. No GPI control or Tally for Output 2
Unless "force" mode is enabled, a GPI input switch will not occur if the input being switched
to contains more significant error conditions than the current input. GPI 5 and 6 can be
configured to show an alarm condition for anyindividual or group of error conditions. Certain
reportable errors such as input missing will result in an immediate indication, whereas other
lesser conditions must be present continuously for a period of time set by the user before an
alarm is asserted. Where a group alarm has more than one preset time delay, an alarm will be
asserted after the longest delay setting.
