Meinberg TCR180, Manual

Page: 18 / 43

7 Functionality of the generator
The time code generator of TCR180 is based on a DDS (Direct Digital Synthesis) frequency generator which
derives the sine carrier of the modulated code from the reference clock of the master oscillator. The modulation
of carrier amplitude (modulated codes) or pulse duration (unmodulated, DC level shift codes) is synchronized to
the generated pulse-per-second (PPS) signalderived from the software clock.
The generated time code is independent from the set-
tings for the received code. Thus it’s possible to gen-
erate a output signal with a different format and UTC
offset than the input signal.
7.1 Time Code Outputs
TCR180 provides modulated and unmodulated (DC level shift) outputs.
7.1.1 Modulated Outputs
The amplitude-modulated sine carrier is available by VG connector. The signal amplitude is 3Vpp (MARK)
and 1Vpp (SPACE) into 50 Ohm. The encoding is made by the number of MARK-amplitudes during ten carrier
waves. The following agreements are valid:
binary ’0’ : 2 Mark - amplitudes, 8 SPACE-amplitudes
binary ’1’ : 5 Mark - amplitudes, 5 SPACE-amplitudes
position-identifier : 8 Mark - amplitudes, 2 SPACE-amplitudes
7.1.2 Unmodulated Outputs
The pulse width modulated DC-signals are coexistent to the modulated output and are available with TTL level
into 50 Ohm and as RS-422 signal.
14 Date: 4th June 2021 TCR180