Grass Valley Imagestore 750 v.3.0.1 - Manual (Page 52)

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Features
Keying Graphics
The following external interfaces to the Imagestore 750 are required:
• Serial input
The EAS receiver connects to the Imagestore 750 over an RS-232 serial connection. This con-
nection provides the EAS alert data including the alert level and crawl text data.
EAS messages can be up to 1990 characters long.
• GPI input
A GPI trigger on the Imagestore 750 is used to initiate, and then terminate, the EAS alert. This
GPI can come directly from the EAS receiver, from automation, or from a manually initiated
trigger.
The GPI trigger drives separate ‘EAS On’ and ‘EAS Off’ macros that allow you to build a cus-
tom branding event around the EAS crawl. The macro usually includes triggering of an AES
voice-over (which will duck the background audio) but can play a pre-recorded Easyplay
audio clip instead.
• Voice-over input
Audio voice-over input is fed into an external AES pair on the Imagestore 750. The EAS audio
message is up to two minutes duration and stored in the receiver until the alert is triggered.
Because most receivers have analog audio outputs, the audio must first be converted to AES
using an external converter (such as the Miranda ADC-1711 or ASD-771p). The AES audio is
then fed to the Imagestore 750 through an external AES input pair and the audio is mixed
with the background through a voice-over:
Fig. 4-4: EAS Receiver interfacing
EAS Crawl Templates
The Imagestore 750 monitors its COM ports for a serial string from an EAS receiver. When a
message is received, its priority (high, medium, low, or none) is established and the text is
updated in one of the following default Easytext crawl templates.
For each video standard, there is a standard set of files that correspond to the appropriate EAS
alert level with the appropriate background color.
EAS Receiver
Data Output
Relay Output
Audio Output
Imagestore 750
Serial Input
GPI Input
Voice-Over Input
RS-232 Message Data and Alert Level
Automation or Manual Override
Analog-to-Digital Conversion
Filename Priority Video Standards
EASHigh.oxa 1 (high) 525i / 59.94, 625i / 50
EASHighHD1080.oxa 1 (high) 1080i / 59.94, 1080i / 50
EASHighHD720.oxa 1 (high) 720p / 59.94, 720p / 50
EASMed.oxa 2 (medium) 525i / 59.94, 625i / 50
EASMedHD1080.oxa 2 (medium) 1080i / 59.94, 1080i / 50
EASMedHD720.oxa 2 (medium) 720p / 59.94, 720p / 50
Table 4-7: Standard EAS alert crawl template Filenames