Network Technologies ASI-IP-GTW User Manual

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ASI-IP-GTW User's Manual 
 
 Page 
58 
Options 
This chapter describes functionality and operating instructions for 
various additional product options. 
4.1  1PPS/10MHz interface modules 
In order to achieve exact bitrate control for use in SFN networks, the 
ASI-IP-GTW may be equipped with 1PPS/10MHz interface modules. 
The purpose is to lock the internal system clock of the ASI-IP-GTW to 
external 1PPS/10MHz signals to obtain exact bitrate control. The 
typical application is to receive a stream over IP network and send it 
out on ASI connectors at a fixed, accurate rate. The transmitter needs 
to transmit at the same rate. 
Two options exist to lock the product to external time reference: A 
separate 10MHz/1PPS module which occupies an ASI slot, or a 
separate 1PPS input module that allows 8 ASI ports. 
4.1.1 Separate 10MHz/1PPS module 
Figure 29 shows a picture of the back panel when this module is 
mounted. 
 
Figure 29. ASI-IP-GTW with 1PPS/10MHz interface module equipped 
The signals are: 
10MHz. 50 ohm terminated input for a sinusoidal 10MHz signal. 
1PPS. 50 ohm TTL input for a 1 pulse-per-second signal. 
For physical parameters of these ports, see appendix B. 
Both signals may be connected. However, the ASI-IP-GTW only uses 
one of them at a time. The active input is selected from the “GPS” tab in 
the ASI-IP-GTW WEB user interface. 
4.1.2 
1PPS interface 
When 8 ASI outputs are required together with SFN operation, an 
alternative to the 1PPS/10MHz module is to use a separate 1PPS 
interface as described in the following figure. 
 
Figure 30. ASI-IP-GTW with separate 1PPS interface module 
The signals are: