Dewetron DEWE-ORION-0824-20 Series, Technical Reference Manual

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DEWE-ORION-0824-20x
2.9.2 Synchronising mutliple systems
If multiple systems or PCI expansion systems are used, a synch-bus repeater (ORION-DSA-SYNC) has to
be used (ordering option ORION-1624-SYNC). This repeater decouples the internal synch-bus with the ex-
ternal synchronization input and out put connector. This gives the possibility to expand the distance between
two systems by up to 35 meters using standard CAT5 Ethernet cables.
Please contact DEWETRON if longer synchronization distance is required! Please also refer to DEWE-
GPS-CLOCK or DEWE-IRIG-CLOCK for additional synchronisation methods.
The ORION-DSA-SYNC also includes the security circuit if two master systems have to be connected to-
gether over the synch bus connection. As soon as the system is configured to a master system the external
synch is ignored by disabling the SYNC-IN amplifier. The LED MI (master internal) indicates if the system is
configured to a master system. ME (master external) is on, if at the SYNC-IN connector a valid SYNC signal
is connected.
DEWE-ORION-0824 DEWE-ORION-0824 DEWE-ORION-082
4
DEWE-ORION-082
4
DEWE-ORION-0824
Collision
detect
Internal synch bus
DEWE-ORION-0824-20x
(LVDS)
Synch out (LVDS)
Synch in (LVDS)
ME MI
Figure 9: Synchronizing multiple systems
The delay of the synchronisation bus within on system is negligible low (<1 nsec). But also the delay of the
ORION-SYNC is lower than 14 nsec (one input and one output amplifier) and will have no significant effect
on the inter channel phase mismatch of the complete data acquisition system. A delay of 14 nsec is nearly
the same delay produced by 3.5 m cable (current time inside the cable)
Optocoupler emitter
Opto collector
Sys-on
Power +5 V
Power GND
To DEWE-ORION-0824-20x Synchbus
Synch in
ME / MI indication
Synch out
ORION-DSA-SYNC
In addition to the synchronization function the ORION-DSA-SYNC allows also to remote power the slave-
system. As soon as a master system is present an opto coupler output (PC817) is activated to switch on the
power supply. The remote power on also can be controlled with an external control voltage (+5 V@Sys-On).