User manual

Configuring with an ASCII Terminal
5-18 Campus-RS Fractional Interface Card User Manual
Inverting the Transmit Clock
There may be circumstances in which it is either desirable or necessary to
invert one or more of the TT, SCT, and SCR clocks. This could be true if the
host equipment provides inverted clock signals, if the differential clock
signals are switched in the data cable, or if there is excessive clock delay. The
Fractional Interface Card allows you to invert any of these clock signals by
changing the appropriate Invert Clock option.
For physical-layer protocols that have unbalanced (single-ended) clock
signals, the Invert Clock option has the effect of simply inverting the clock
signal. This appears as a 180° phase delay. For physical-layer protocols
which have balanced (two-wire) clock signals, the Invert Clock option has the
effect of switching the inverting and non-inverting contacts.
There are two settings for each Invert Clock option:
• OFF leaves the output clock in its normal, non-inverted, state.
• ON inverts the clock signal or, for the TT input, inverts the input signal
internally.
To invert the input clock (TT):
1 From the Data Port Settings menu, type then press . The Invert
Input Clock option changes to the next available setting.
2 Repeat the previous step until the Data Port Settings menu displays the
desired invert clock setting.
To invert the output transmit clock (SCT):
1 From the Data Port Settings menu, type then press . The Invert
Output TX Clock option changes to the next available setting.
2 Repeat the previous step until the Data Port Settings menu displays the
desired invert clock setting.
To invert the output receive clock (SCR):
1 From the Data Port Settings menu, type then press . The Invert
Output RX Clock option changes to the next available setting.
2 Repeat the previous step until the Data Port Settings menu displays the
desired invert clock setting.
5 ENTER
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