Technical data

Installation & Operation Manual GM-TTT
Page 82
7.6 Analogue Master Output
Option A: this option requires an additional hardware. This option can be installed together
with option DCF IN or GPS IN.
With this option a distribution amplifier supplies the analogue clocks of the Alpermann+Velte
MTD system with power as well as with time data. The time data forms a telegram similar to
the German radio time telegram DCF77. The data bits are transmitted every second except at
seconds = 59. The time data are synchronous to the P_SEC signal of the built-in DCF or GPS
receiver. The time exactly corresponds to the time which is transmitted by the built-in DCF or
GPS receiver.
Below the pin assignment of the DSUB9 female connector GPI and a wiring example:
from Master Output to Analogue Clocks
DSUB9F open ends (to screwing posts)
1: V+ Out Vdd (1)
2: V- Out GND (2)
7: Signal Out Signal (3)
8: Signal GND GND (4)
The pins not specified should not be used. Use e.g. a two-paired, twisted cable, twist 1 with 2
and 7 with 8.
Every slave clock requires <=11mA at >=6V. To calculate the maximum cable length the
output voltage, cross section, specific resistance and number of clocks have to be involved.
For radial arrangement of copper cables with a cross section of 0,22mm² and a output
voltage of 12V, the following cable lengths are possible:
no. of clocks 1 2 5 10 20 30
length (m) 3500 1750 700 350 175 117
The maximum count of clocks is limited by a 300mA fuse to 30 clocks. A control LED at the
front is directly connected to the signal output:
30
25
free
mod.
cf Signal Out
This option changes the technical data of the unit. Use only the AC/DC adapter
delivered with the unit!
Item Specification
Input voltage 10 -18 V DC (instead of 10 - 30 V
DC)
Power
(GM-TTT with Option GPS IN + Option A)
typical 6 W, max. 11 W