Symmetricom XLi IEEE 1588 - Manual (Page 64)

56 XLi IEEE 1588 Clock
997-01510-03, Rev. C, 12/12/2006
S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S
1
59 GPS antenna cable supplied with the XLi. If the GPS antenna is connected using a different antenna
length, calculate the new value using the multiple given below and adjust the value of F51. If using an
optional Down/Up Converter, consult that product’s documentation for directions on setting the correct
cable delay.
F51 Guidelines:
• For RG-59: multiply the cable length by 1.24 ns/ft. to get the value for F51.
• For RG-58: multiply the cable length by 1.4 ns/ft. to get the value for F51.
• Don’t use function F51 to adjust the XLi’s timing outputs; use F52 Distribution Cable Delay
instead.
Command Line
Use the following format to display the current Antenna Cable Delay setting:
F51<S>B<N><CR>
The XLi responds using the following format:
F51<S>B<N><SEP><SIGN><DELAY>ns<CR><LF>
where:
For example, to see the antenna cable delay for the GPS card in option bay 4, enter:
F51 B4<CR>
XLi responds:
F51 B4 +000060ns<CR><LF>
F = ASCII character F (f or F for input string).
51 = the function number.
<S> = ASCII space character one or more.
B = ASCII letter to denote Option Bay number follows
<N> = Option Bay Number of the GPS option card, 1 through 4.
<CR> = carriage return character.
<SEP> = one or more space characters.
<SIGN> = either + or blank
<DELAY> = 1 to 6 digit delay from 0 ns to 999999 ns.
ns = nanoseconds (ns or NS for input string).
<LF> = line feed character.