TouchLine Key Signaling

Signaling protocol

The analog station interface uses two types of signaling protocols, Current Signaling and Tone Signaling

Current Signaling

The a/b-wires are the loudspeaker wires, and the c/d-wires are the microphone and digit selection wires. Approximate current values are (the currents in a/b-wires for display station is shown in brackets):

a/b-loop:

On-hook: 3mA (13 mA)
Off-hook: 0 mA (10 mA)
M-Key: 10 mA (20 mA)
C-key: 20-25 mA (30-35 mA)

c/d-loop:

ID (key press): 10 mA
Open: < 1 mA
Private: 3 mA

Digit Signaling

Station keyboard digits 0 - 9 use sinewave tones in the range 500Hz to 2300 Hz, at 200 Hz steps.

Digit 0: 500 H
Digit 1: 700 Hz
Digit 2: 900 Hz
Digit 3: 1100 Hz
Digit 4: 1300 Hz
Digit 5: 1500 Hz
Digit 6: 1700 Hz
Digit 7: 1900 Hz
Digit 8: 2100 Hz
Digit 9: 2300 Hz

Extended Digit Signaling

In addition to the keyboard digits 0 - 9 another set of 10 tones are used for DAK signaling for CRM IV, Dual Display and PrisCom stations.

These tones 10-19 are sinewave tones in the range 600Hz to 2400 Hz, at 200 Hz steps.

DAK Signaling

DAK (Direct Access Key) is the speed-dial buttons on the station.

Master stations

Master station DAK keys use a combination of current signaling (M) and digits:

DAK 1: M + digit 0
DAK 2: M + digit 1
DAK 3: M + digit 2
DAK 4: M + digit 3
DAK 5: M + digit 4
DAK 6: M + digit 5
DAK 7: M + digit 6
DAK 8: M + digit 7
DAK 9: M + digit 8
DAK 10: M + digit 9

When "Hot-line" function is enabled, Off-Hook is mapped to DAK 7 and On-Hook to DAK 8.

CRM IV and Dual Display Stations

CRM IV and Dual Display Stations also use a combination of current signaling and digits:

D1-D10: M+0 - M+9
D11-D20: digit 10-19
D21-D30: M+10 - M+19
D31-D40: C+0 - C+9
D41-D50: C+10 - C+19
D51-D60: (Prefix +) M+0 - M+9
D61-D70: (Prefix +) digit 10-19
D71-D80: (Prefix +) M+10 - M+19
D81-D90: (Prefix +) C+0 - C+9
D91-D100: (Prefix +) C+10 - C+19

Prefix = ID+C

Priscom Stations (7061/7063)

Priscom Stations (7061/7063) use so called Two Tone DAK Signaling which is a combination of Extended Digit Signaling and Digit Signaling:

Key board digit 0-9: Digit Tone 0-9

DAK D1-D15: Digit tone 10 + 0 to 10 + 14

DAK D16-D30: Digit tone 11 + 0 to 11 + 14

DAK D31-D45: Digit tone 12 + 0 to 12 + 14

DAK D46-D60: Digit tone 13 + 0 to 13 + 14

DAK D61-D75: Digit tone 14 + 0 to 14 + 14

DAK D76-D90: Digit tone 15 + 0 to 15 + 14

DAK D91-D100: Digit tone 16 + 0 to 16 + 9

Optional DAK Acknowledge

Priscom stations using Two Tone DAK Signaling can be configured with acknowledge on DAK keys:

The AMC application will send an acknowledge message by the Display Text Protocol.
The station will acknowledge this by sending tone 18.

Optional IND Acknowledge

Priscom stations using Two Tone DAK Signaling can be configured with acknowledge on IND messages sent to the station:

The AMC application will send the IND message by the Display Text Protocol.
The station will acknowledge this by sending tone 17.

If no acknowledge from the station within 2 second the IND message is resent once.

Substations

Substations use current signaling only:

DAK 1: ID
DAK 2: ID + M
DAK 3 ID + LT (off-hook)