EGi GES 400 MR, Руководство пользователя

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GES 400 MR Series User Manual | 8100401-55 • 2015-07-22
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Table 4-1. Net Amps clock sync front panel connections and indicators
Callout
Connection/
Indicator
Description
System LEDs Indicate the system’s status.
Power (top). When illuminated, the Net Amps clock
sync is powered.
Link (middle). When illuminated, the amplifier and
clock sync are connected, working, and
communicating with each other.
Lock (bottom). When illuminated, the PLL (phase
lock loop) of the amplifier is locked to the MR
clock of the MRI scanner. Locking occurs about
one minute after the clock sync is powered.
PLL Lock (Hz)
LEDs Indicate which clock frequency the PLL is locked to.
The default frequency is 10 MHz. One frequency is
available for custom applications.
Signals LEDs Indicate whether or not the various system signals
have been detected.
Ext. Clock (top left). When illuminated, the external
MR clock input is detected and active.
TR (middle left). When illuminated, the clock sync
detects the MR system’s TR pulse. Detection
occurs about two seconds after the MRI scanner
begins scanning (and pulses once for each head
volume scanned thereafter).
ADC Reset (bottom left). Works in conjunction with
the Reset Armed LED—this LED responds second .
The ADC Reset process is used to ensure that the
TR pulse is not sampled when it is changing.
Specifically, after the ADC Reset process is
initiated and the first TR pulse is detected, this
LED illuminates and the ADC (analog-to-digital
converter) is reset to align with the TR pulse (plus
a 10 microsecond delay). This LED extinguishes
when the process is complete.
Reset Armed (top right). Works in conjunction with
the ADC Reset LED—this LED responds first . The
Reset Armed process is used to ensure that the
ADC Reset process occurs only once per MRI scan.
Specifically, if no TR pulse is detected for the first
30 seconds of an MRI scan, then this LED
illuminates and the ADC Reset process is