Instruction manual
The Control Unit
1-5
Introduction
024 TDL Module 1
The 024 TDL module contains 24 extension ports for connection to the 4400- 
Series telephones. The module has potential operator positions at the first, fifth, 
thirteenth, and seventeenth ports. If the 024 TDL module is in Slot 1, you can 
connect a 4424LD+ telephone to the first extension port and use that telephone 
as the system programming console. This module can fit into both metal and 
plastic carriers.
Only a 4424D+ or 4424LD+ telephone can be connected to an eligible 
operator position port assigned as a Direct-Line Console (DLC) 
operator position; only a 4424LD+ telephone can be connected to an 
eligible operator position port assigned as a Queued Call Console 
(QCC) operator position. If an invalid type of telephone (for example, 
a 4400, 4400D, 4406D+, or 4412D+) is plugged into a port assigned 
as an operator position, the system programming console displays a 
message indicating that the 4400-Series telephone is invalid. If the 
programming console has a Direct Station Selector (DSS) connected, 
the LED associated with the invalid telephone type turns on and 
remains on until a valid type of telephone is connected to the port.
As with MLX modules, the slot/port numbering for adjunct ports on 
412 LS-ID-TDL modules begins at 21. The slot/port numbering for 
adjunct ports on a 024-TDL module begins at 25. For example, on a 
412 LS-ID-TDL module in slot 1 of the carrier, to access adjunct port 
710, you would enter 0121 as the slot/port number (01 indicates slot 
1 on the carrier). On a 024-TDL module in slot 1 of the carrier, to 
access adjunct port 710, you would enter 0125.










