diu, astrotac3000, quantar v.24 external clock

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stan
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diu, astrotac3000, quantar v.24 external clock

Post by stan »

I am trying to connect the diu to the astrtac3000 via PTP microwave, and from the comparator to the site located quantar via microwave. I belive i should set all the components to extrnal clock. can anyone provide some input from previous experience?

Thanks.
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Astro Spectra
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Re: diu, astrotac3000, quantar v.24 external clock

Post by Astro Spectra »

Hi Stan, heaps of material here just search using keywords Quantar and clock.

There is no hard and fast rule, you have to design your clocking strategy based on your specific equipment (mux cards, etc), backhaul implementation (for example is the microwave or other backhaul circuit telco provided), etc.

Also what manuals have you got already?
wa6ylb
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Re: diu, astrotac3000, quantar v.24 external clock

Post by wa6ylb »

stan wrote:I am trying to connect the diu to the astrtac3000 via PTP microwave, and from the comparator to the site located quantar via microwave. I belive i should set all the components to extrnal clock. can anyone provide some input from previous experience?

Thanks.
The rule of thumb is, that if your transporting the V.24 from one device across a microwave or other transmission device (i.e. lease line modem, channel bank), you should use the
clock signal being generated by the microwave / transportation device itself. A typical installation from days gone by, used Permisys (now named Zhone) channel
banks to transport the 9600 baud sync (V.24) circuit (via SRU card), as well as 4 wire audio (E&M card or DSM II) across the microwave, as part of a T1 carrier. The idea is to let the
timing of the T1 channel itself dictate the clock of the circuit as well. This allows the data to stay in sync across the entire microwave, thus preventing lost V.24 data bytes.
In the case of the channel banks, the Sub Rate Card (SRU) generates the clock signal to gate in or out the data from the DIU or Astro Tac 3000, or between DIU or Astro Tac 3000 and Quantar etc.

There are two settings on the wireline card (Switch 1 on, switch 2 off, or Switch 1 off, switch 2 on – this is the only choices)- one for internal sync, and the other is external sync. Internal sync is when
you have two devices in the same general area, where you can run a "Null" V.24 cable (cross over cable) between the devices, and since they are so close, there isn't anything electronic that could delay the signals. The external setup allows the user to use straight through V.24 cables, between the device and a Premisys channel bank SRU card.

In the case of your PTP microwave, check to see if their V.24 interface supports external clock. You really should use it in the transportation of sync V.24 on the microwave.

I’ve done quite a bit of these connections, bring astro tac receivers and or Quantars back to Astro Tac 3000 comparators.

B.
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chartofmaryland
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Re: diu, astrotac3000, quantar v.24 external clock

Post by chartofmaryland »

Not seeing your Synchronous Serial interface for V.35, V.24 TIA/EIA RS-232 traffic.

The serial interface is what plays traffic cop to your data packets containing the timing

If you are not running an HDLC interface such as thehttp://www.dcbnet.com/datasheet/est9600ds.html

Or a Cisco router with an HDLC serial interface.

If there is an IP or T1 capable mux running around you can use a Telenetics / Raymar modem configured for Leased line where you can run full duplex between your mux's
If the lights are out when you leave the station and then come on the second you key up, you know you have enough power.
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