Tac/Com Control Head Manual

SM06 Rev. 4.10

The additional codes and frequency display were added in the new control head software in 1991 for USFS/OAS contracts. Tone data is often received in the EIA sequential number format, or as the raw frequency, and requires additional tone support for ease of use. Controls with USFS interfaces (guard controls) are set for the EIA sequential tone code at the factory. Older controls (pre-1991 Tac/Com II) may upgrade to current generation software for this expanded tone display.

3.5.4.3Using Help to Get the Table

The tone code table is accessed by pressing HELP while editing a tone location during channel editing. Scroll through the table by pressing HELP until the desired entry is located. Press RADIO to exit, or continue through the table by pressing HELP until the data entry screen is reached.

3.5.4.4DPL Codes

NAT NT-series transceivers support 83 Digital Private Line Codes (DPL) in addition to the CTCSS or Private Line subaudible tones. This option must be enabled at installation time in the installation and configuration mode of operation. It is normally shipped set to OFF by the factory to reduce confusion over tone codes.

DPL codes are three digit sequences that describe a digital code sent at low frequency in the background of regular transmissions. They are filtered out of normal receive audio and provide another method of signalling or squelch control.

Code numbers are arbitrary and are stored in an internal table. When in use, the control head finds the correct entries based on how the code is entered. The FREQ option for tone presentation is not available if DPL is enabled.

023

DPL Code

If the '0' position is chosen for edit, the control head is

 

 

programmed to select a 3-digit DPL code and bring up the

 

 

table for the SELECT switch to choose from.

32

Tone Code

If the first digit position is skipped, the control head is tone

 

 

code programmed to select a 2-digit CTCSS tone code and

 

 

bring up the table for selection.

This arises ONLY if DPL is enabled. For most users, this selection will not be used because only subaudible tones are used.

Page 3-18

Jan 4, 2006

ENG-FORM: 806-0106.DOT

 

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