DS-30X

DS-30X
Media	Copper
# of Signals	4
Symbol Rate	2.56 MBaud
Variants	DS-30, DS-30A, DS-30Y

DS-30X Speech Links are used to carry speech and some signalling on Norstar Modular platforms.

Physical

• Four wires (arrows are controller <-> card)
  • Tx PCM →
  • Rx PCM ←
  • 5.12MHz Clock →
  • 1kHz Frame Sync →

Electrical

• Signal levels unknown
• Isolation unknown

Logical

• Clocked at 2.56MHz (half the 5.12MHz clock received from the controller)
• Carries 32 channels of PCM voice data
• Each channel consists of a 10-bit word
  • 8 bits of voice data (called a "timeslot")
  • 1 bit of signalling data
  • 1 bit indicating "data valid"
• Signalling data is sent in 24-bit words, one bit at a time in each channel.
  • Sent in both directions, one on Tx PCM and one on Rx PCM