ADLINK PXI-2208 - Manual (Page 94)

82 Operation Theory
System Synchronization Interface
SSI (System Synchronization Interface) provides the DAQ timing
synchronization between multiple cards. In DAQ-/DAQe-/PXI-
2204/2205/2206/2208 card, we designed a bi-directional SSI I/O
to provide flexible connection between cards and allow one SSI
master to output the signal and up to three slaves to receive the
SSI signal. Note that the SSI signals are designed for card syn-
chronization only and not for external devices.
In PCI form factor, there is a connector on the top right corner of
the card for the SSI. Refer to section 2.3 for the connector posi-
tion. All the SSI signals are routed to the 20-pin connector from the
FPGA. To synchronize multiple cards, users can connect a special
ribbon cable (ACL-SSI) to all the cards in a daisy-chain configura-
tion.
SSI Timing Signal Setting Function
SSI_TIMEBASE
Master Send the TIMEBASE out
Slave
Accept the SSI_TIMEBASE to replace the internal
TIMEBASE signal.
SSI_ADCONV
Master Send the ADCONV out
Slave
Accept the SSI_ADCONV to replace the internal
ADCONV signal.
SSI_SCAN_START
Master Send the SCAN_START out
Slave
Accept the SSI_SCAN_START to replace the internal
SCAN_START signal.
SSI_AD_TRIG
Master Send the internal AD_TRIG out
Slave Accept the SSI_AD_TRIG as the digital trigger signal.
SSI_DAWR
Master Send the DAWR out.
Slave
Accept the SSI_DAWR to replace the internal DAWR
signal.
SSI_DA_TRIG
Master Send the DA_TRIG out.
Slave Accept the SSI_DA_TRIG as the digital trigger signal.
Table 4-10: SSI Timing Signal and Functions