Ampex Data Systems ATM 300 ユーザーズマニュアル

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3
 
Multiple ATM 300S/M Connections
 
1.5
Multiple ATM 300S/M Connections
 
To synchronize data transfers to and from the multiple tape drives, connect a user supplied 
SyncStart signal to multiple ATM 300S/M units. The SyncStart signal synchronizes the data 
transfers to the tape drives during record, and from the tape drives during playback. Figure 3 
shows a record/playback configuration across multiple tape drives with synchronized OC-3 
interfaces.
The SyncStart signal is a level sensitive transistor-to-transistor logic (TTL) signal. A high 
(high TTL level or no connection) signal enables data to and from the tape drive. A low (low 
level TTL or ground) disables data to and from the tape drive. Tie all SyncStart inputs to a 
common control signal to synchronize data transfers across multiple tape drives.
The ATM unit internally debounces the SyncStart signal so that the low-to-high transition 
enables data to flow immediately. For high-to-low transitions, the unit debounces the signal 
for approximately 3 ms before it disables the data flow. Therefore, if you use a toggle switch 
or relay to provide a contact closure to ground as the SyncStart input, then the first disconnect 
from ground will enable data flow. If the switch or relay is noisy and produces bounces back 
to ground, the data flow will remain enabled. Only a 3-ms or greater low level signal will 
disable the data flow. (Typically, switch or relay contacts open with much less noise than when 
they are closed.)
 
Figure 2. Single OC-3 Connection
RECEIVER
TRANSMITTER
FRONT PANEL
HOTLINK
INTERFACE
OUT
IN
ATM 300 SERIES
SERIAL IN
SERIAL OUT
DIS 160i
FIBER OPTIC
DEVICE
REAR PANEL
NOTE: SEE TABLE 1 FOR CABLE AND CONNECTOR SPECIFICATIONS.