Grass Valley Imagestore 750 v.3.0.1 - Manual (Page 225)

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Imagestore 750
User Manual
Input to GPI
Where a GPI port is used as an input, the command macro with which it is associated can be
activated either by connecting or by disconnecting the input line to GPI ground (GPIO pin 13 or
15) depending whether ‘GPI On’ or ‘GPI Off’ has been assigned to the port.
Output from GPI
A GPI port can be used as an output and its active status (on) is defined by the output being
internally pulled to ground by a Darlington transistor. (Active low is represented by +0.7
V or
less.) Lamps or relays attached to an output port can use either the GP +12 V supply (pin 8) or GP
+5 V supply (pin 7) but the maximum current drawn from either supply should not exceed
500 mA. These supplies are fused.
Where a GPI output is used to drive a relay coil, you should incorporate reverse voltage protec-
tion diodes in the circuit to protect the Imagestore 750 from voltage transients.
LTC Connection
Where linear timecode is provided for the Imagestore 750, it should conform to ANSI/SMPTE
standard 12M-1995. The input level should be between 1.0 and 2.0 volts peak-to-peak.
AC Input
The Imagestore 750 is equipped with two 350 W power supply units, each fed from its own rear
IEC connector. The power supplies are auto-ranging from 100–120 VAC and 200–240 VAC.
Fig. 12-12: Rear Pael Connectors - IEC Mains AC Inlets
Applying Power
Each of the two power supply units (PSU) of the Imagestore 750 has a power switch that
becomes accessible when you remove the front fascia. The Imagestore 750 should be
connected to main power with an appropriate circuit breaker on each circuit.
After power is applied, the Imagestore 750 will boot automatically. The normal complete boot
process takes about 50 seconds, or approximately 90 seconds after a software upgrade. Addi-
tional time should be allowed for advanced audio module firmware upgrades.
Before applying power, ensure that the USB port does not contain a USB device. When starting
up, the Imagestore 750 first checks to see if there is a USB device present. If it finds one, it will
attempt to boot from that device. Note that this USB port is hidden by the front fascia.