VISTEK V165X serialdigital
video routermodule
HU-V165X 7
SW12
Switch 12 is onlyfitted on the V1651 and the V1653 and can be divided into two halves. The switches 1-4
control the synchroniserdelayforboth routersand the switches 5-8 are used bythe V6151 to determine the
conditionsfor an automaticchange over of sources.
Switch 1 (V1651 only)
This switch turns offthe synchronising function and reduces the delayof eachchannel to aminimum. This is
the recommended mode ofoperation if an external reference is never provided.
Switches 2-4
Theseswitchescontrol the amount ofdelayadded to the signal path with respect to the referencesignal
being used. This will allow the synchronising mechanismto timesignalsearlyon the referenceupto 4000
clockcyclesminusthe selected delay, or late on the reference upto the selected delay. (See table).
Approximate selected delays. (wrt selected reference).
SW12 Approx.Delay(us)
2 3 4 143Mbits/s
177Mbits/s270Mbits/s360Mbits/s
0n 0n 0n -179, +0.7 -225, +0.5 -147, +0.5 -109, +0.3
0n 0n 0ff-177, +3 -224, +2 -146, +1.5 -109, +1
0n 0ff 0n -173, +7 -220, +6 -144, +3.5 -107, +3
0n 0ff 0ff-264, +16 -213, +13 -139, + 9 -104, +6
0ff 0n 0n -245, +35 -197, +28 -130, +18 -97, +13
0ff 0n 0ff-210, +70 -169, +56 -111, + 37 -83,+27
0ff 0ff 0n -175, +105 -142, +84 -93, +55 -69, +41
0ff 0ff 0ff+140 +113 +74 +55
* WARNING * Careshould be taken when setting the delay,aspicturedisturbanceswill occurif the
FIFO minimumor maximumlengthsare reached.
Switch 5 (V1651 only)
Thisswitch allowsthe unit to selectbetween synchronous and Non-synchronous switching modes according
to whether an external reference ispresent and being used. Ifthe unitslink2is in EXT and areference is
provided the router will operate with synchronous switching. If link2isset to INTor the referenceisnot
present the unit will change to non-synchronousmode automatically.
