Sierra 200 owner manual Digital Pot Controls for Audio Level Setting

Digital Pot Controls for Audio Level Setting

The system contains multiple digital potentiometers used to set or “trim” various audio levels. There are two digital pots on the main CPU board and four digital pots on each of the radio control boards (RCB). Each pot can be set to a value between 0 and 255 where 0 is minimum, or no audio, 127 is midscale, and 255 is max audio.

There are two ways to set the digital pots: setting a specific value and setting a value interactively. Setting a specific value simply takes the value parameter and immediately sets the pot to that value. The interactive pot set will allow value increment and decrement without sending the whole command string. This is similar to the old way of adjusting a mechanical pot.

CPU Board

Pot 0

Pot 1

Pot 2

Pot 3 CPU telemetry

RCB Board

Pot 0 External audio input (typically sub-audible tone encoders) Pot 1 Transmit audio

Pot 2 Receive audio

Pot 3 RCB local telemetry

C223 (u) Set radio pot Sets one digital pot value.

Syntax is *C223rpv

r is the physical port (0..8, where 8 is the cpu card)

pis the pot (0..3), v is the value (0..255)

C224 (u) Set radio pot interactive Sets the value of one pot, interactively. Syntax is *C224rp…..D

r is the physical port (0..8,) where 8 is the cpu card p is the pot (0..3)

…. is a sequence of keystrokes to interactively set the pot value

1 and 7 increment and decrement the pot value by 1 2 sets the pot value to 255

5 sets the pot value to 127

8 sets the pot value to 0

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