Grass Valley Imagestore 750 v.2.0.1 - Manual (Page 281)

Imagestore 750 User Manual Installation
Miranda Technologies Inc. Page 281
Connection of General Purpose Interfaces
(GPIs)
The General Purpose Interface port may be used either to trigger the
execution of a series of internal pre-programmed commands (input) or to
monitor the status of the Imagestore 750 (output). The process of assigning
command macros to an individual GPI port is described in the Front Panel
commands section on page 134. All GPIs can be assigned as either an input
or an output.
Input to GPI
Where a GPI port is used as an input, the command macro may be activated
by either connecting or disconnecting the input line to GPI ground (pin 13 or
15) depending whether ‘GPI On’ or ‘GPI Off’ has been assigned.
Output from GPI
A GPI port may used as an output and its active status (on) is defined by the
output being internally pulled to ground by a "Darlington" configured
transistor such that an active low will be represented by +0.7V. Lamps or
relays attached to an output GPI may use the GP +12V supply (pin 8) or
GP_+5V supply (pin 7) but the maximum current drawn from either supply
should not exceed 500mA. These supplies are fused.
Where a GPI output is used to drive a relay coil, reverse voltage protection
diodes should be incorporated in the circuit to protect the Imagestore from
voltage transients.
Connection LTC
Where linear timecode is provided for Imagestore 750 it should conform to
ANSI/SMPTE standard 12M-1995. The input level should be between one
and two volts peak-to-peak.