DECT Sync pinout and signal details

Clear-Com uses the ETSI DECT Sync signal. Below this text is an excerpt from the spec.

Explanation of DECT sync can be found here https://clear-com.atlassian.net/wiki/spaces/SF/pages/158685179

The DECT sync signal appears across pins 3 and 6 of the E1 / Antennas RJ5 connector on the rear of the E-Que card

The FSII (E1) Antenna uses all 8 wires of the CAT5 cable on an E1 pin out when wired back to a splitter, base station or directly to an E-Que card.

E1 / Antenna RJ45

Function

E1 / Antenna RJ45

Function

Pin 1

TX Tip +ve

Pin 2

TX Ring –ve

Pin 3

DECT Sync +ve (For Cellcom/ FreeSpeak connection to Antenna)

Pin 4

RX Tip +ve

Pin 5

RX Ring –ve

Pin 6

DECT Sync –ve

Pin 7

GND

Pin 8

 +12V (From base or splitter – No power from E-Que rear)

It’s a 100 HZ pulse train with the positive pulses about 880 µs wide, and every 16th pulse is 2640 µs , three times as wide.  

This same signal also appears on the dedicated DECT IN / OUT RJ45 connectors on the EQUE card / FSII Base  . The dedicated DECT Sync In / OUT connectors allows the user to pass Dect sync to other stand-alone DECT matrix / basestation or 3rd party devises who maybe sharing the same RF space

The pin out for the dedicated DECT Sync IN / OUT RJ45 is

DECT Sync IN Connector

 

DECT Sync IN Connector

 

Pin 1

DECT_SYNC_IN-

Pin 2

DECT_SYNC_IN+

Pin 3

8KHZ_IN+

Pin 4

 

Pin 5

 

Pin 6

8KHZ_IN-

Pin 7

 

Pin 8

 

DECT Sync OUT Connector

 

DECT Sync OUT Connector

 

Pin 1

8KHZ_OUT+

Pin 2

8KHZ_OUT-

Pin 3

DECT_SYNC_OUT+

Pin 4

 

Pin 5

 

Pin 6

DECT_SYNC_OUT-

Pin 7

 

Pin 8

 

 

B.2.1 Synchronization signal

  • The synchronization signal  is a 100 Hz signal having positive pulses of width between 5 μs and1 ms, except for frame 0 (every 16th pulse), which has a pulse width between 2 ms and 5 ms. This signal establishes the10 ms DECT frame interval and the 160 ms DECT multiframe interval.

  • The synchronization signal shall have a long term frequency accuracy of better than ± 5 ppm (nominal conditions) or± 10 ppm (extreme conditions).

  • As the wave form is asymmetric, devices can establish proper timing relations in the event that the differential pair of input signal wires is (improperly) connected (pair inversion).

  • The random phase jitter on the falling edge of the synchronization signal shall not exceed 0,5 μs rms. The differential amplitude shall be greater than 400 mV peak to peak.