Technical data

Installation & Operation Manual GM-TTT
Page 81
7.5 Seconds and Minutes Pulse Output
Option P: this option requires an additional hardware. When displaying the equipment status
(after power-on or pressing the enter button with deactivated menu), it is possible to check, if
this option is present:
• At first step of status display digit 1 shows an “o“.
• At second step of status display digits 2 and 1 show the identification “03“.
The pulses have TTL level (0-5 V) and are connected at female DSUB GPI or - when
application with AS-TTT is required - at female DSUB MTD:
Signal Connector GPI Connector MTD
Seconds Pulse Pin 3 Pin 6
Minutes Pulse Pin 4 Pin 7
GND Pin 5 Pin 8
The pulses are locked to the LTC output and are triggered from the time of the internal clock.
Using the pulses together with the time information of the LTC the main operating mode time
has to be selected.
The polarity of the pulses can be selected at menu SET - ... - F-RATE:
Digit 8
Digit 7 Digit 6 Digit 5
Digit 4
Digit 3
Digit 2 Digit 1
Digit 6 = H “High” = positive pulse
Digit 6 = L “Low” = negative pulse
The following diagram shows the detailed timing.
The seconds pulse starts one LTC bit before the beginning of the first frame of the new second
(leading edge = reference mark). The pulse duration is equal to one LTC frame.
The edges of the minutes pulse occur approximately 15 µs before the reference mark of the
seconds pulse. The pulse duration of the minutes pulse is equal to one second.
Seconds Pulse "H"
Seconds Pulse "L"
LTC Output
First frame of the new second
Bit 79
Bit 0
Seconds Pulse "H"
Minutes Pulse "H"
Seconds Pulse "L"
Minutes Pulse "L"
15 µs
First second of
the new minute