Mitel 3300 ICP Hardware User's Manual page 76

3300 ICP Hardware User Guide
• Constant current design with the loop current set at 25mA. If the loop range extends pass
600 Ohm, this circuit will revert to a voltage feed of approximately 2xVdc (design dependant
parameter between 22-26 Vdc). The circuit remains active and the loop current will be
dependant on the external loop impedance.
• Supports a Ringing Equivalent Number (REN) of 3.
• Capable of on-hook transmission. Used in conjunction with a centralized resource to de-
liver calling line ID.
• Positive disconnect (removal of battery from the ring lead).
• Battery reversal (UK< LA< EU variants only - used for CLID).
• Ground button detection.
• Message waiting indication (dc voltage method).
• Message waiting indication (class message).
• Status led indicator per circuit.
• Low level diagnostics.
ONS Transmission Parameters (ASU)
Transmission
Input Impedance
Balance Impedance
Digital Coding
Transmission
Input Impedance
Balance Impedance
Digital Coding
ONS DC Supervision Parameters (ASU)
DC Supervision
Battery Feed
Loop Resistance
Loop Detect Threshold
Flash Detect
Ground button detect
threshold
Positive Disconnect
68
Parameters for NA
600 ohms
600 ohms
ITU µ-law – MT8966 CODEC
Parameters for LA
600 ohms
600 ohms
ITU µ-law – MT8966 CODEC
Parameters for NA/LA
-30Vdc feed, constant current set
at 25mA +/- 1mA
600 Ohms (includes set)
12mA
SW timed function from switch
hook detector
13mA Tip or Ring to ground in off
hook state
SW timed function that breaks loop
current
Release 3.3
Parameters for UK
300R + (1000R // 220uF)
300R + (1000R // 220uF)
ITU A-law – MT8967 CODEC
Parameters for EU
270R + (750R // 150uF)
270R + (750R // 150uF)
ITU A-law – MT8967 CODEC
Parameters for UK/EU
-30Vdc feed, constant current
set at 25mA +/- 1mA
600 Ohms (includes set)
12mA
SW timed function from SWHK
detector
13mA tip or Ring to ground in
the off hook state
SW timed function that breaks
loop current