TRBOnet Swift Agent is a hardware ROIP (radio-over-IP) gateway developed for connecting to MOTOTRBO stations. It can be used for connecting to other stations in analog mode also.
In the body of the article, we consider various ways of connecting to non-MOTOTRBO stations in analog mode.


There are three prerequisites for a non-MOTOTRBO analog control station to be able to connect to a TRBOnet Swift Agent:

1. A non-MOTOTRBO analog control station is able to be connected to a TRBOnet Swift Agent through 4 PINs at a minimum: Audio IN/Audio OUT, External PTT, CSQ detect (Channel Activity).

2. PINs such as External PTT and CSQ detect (Channel Activity) should be configured correctly both on a non-MOTOTRBO analog control station and a TRBOnet Swift Agent.

3. A power supply should be connected appropriately to both a non-MOTOTRBO analog control station and a TRBOnet Swift Agent.

Step 1: The logical connection scheme between an Agent and an analog station

On the picture below the logical connection scheme between an Agent and an analog station is shown.
An analog control station is connected to a Swift Agent A200 with a back audio socket:
By default, the gain on audio jack is turned off.

It corresponds with the default position of sliders in Swift CPS (on the screenshot below):

The magnitudes of the levels of analog audio signals for Swift Agent by default:
Output = 80mV;
Input = 330mV.
It’s the voltage levels that are recommended by default for communication with Motorola’s MOTOTRBO stations through its accessory receptacle.

The extreme sliders position shows what the maximum voltage level a Swift Agent is capable of receiving from and transmitting to an analog control station.

If a connected control station is not able to lower the magnitude of the voltage it transmits from 30mV ~ 3V, it is required to use an attenuator in order to prevent the Swift Agent’s receptacle from being damaged.

Step 2: Configuring the External PTT, CSQ detect (Channel Activity) command PINs

a) External PTT
The scheme of the command PIN is below:
By default, activation of External PTT is set to the ground – Active level Low (this activation mode is easier to detect at a contact), and deactivation when a voltage of +5V is received.

For more precise detection of contact’s detachment, +5V Pullup is turned on by default. (a pull up resistor is added just to keep the pin to one particular state rather than it to be in a floating state; on a given scheme a pullup of +5V is used)

The pullup of +5V could be activated on both a control station and a Swift Agent’s side, or on both devices at the same time.

By default, Output PTT is set to the 5^th PIN with Pullup of +5V:
A Swift Agent also could use the 7^th PIN for operating with analog stations with Pullup set to +12V.
b) CSQ detect (Channel Activity).

The scheme of the command PIN is below:
By default, activation of the Input CSQ (Channel Activity) PIN is set on the 6^th PIN.

By default, activation of the CSQ detect (Channel Activity) PIN is set to the ground – Active level Low (this activation mode is easier to detect at a contact), and deactivation when a voltage of +5V is received.
For more precise detection of contact’s detachment, +5V Pullup is turned on by default.
To be more precise with this configuration, here are the voltage level threshold values:
Pin On > 2.5V
Pin Off < 1.9V

The pullup of +5V could be activated on both a control station and a Swift Agent’s side, or on both devices at the same time.


Debounce – it’s the PIN activation’s delay period to remove the small ripple of current that forms when a mechanical switch is pushed in an electrical circuit and makes a series of short contacts. (it helps to hinder empty/false voice session when a disturbance interfering on a carrier frequency takes place). It’s set to 100ms by default.

If +5V Pullup is turned off, in the drop-down list for a contact activation which should be taken into consideration during configuring an analog station.

Logic Level1.8V	Pin Off < 0.63V	Pin ON > 1.17V
Logic Level3.3V	Pin Off < 0.8V	Pin ON > 2.0V
Logic Level5V TTL	Pin Off < 0.8V	Pin ON > 2.0V
Logic Level5V TTL CMOS	Pin Off < 1.5V	Pin ON > 3.5V
Logic Level9V	Pin Off < 2.7V	Pin ON > 6.3V
Logic Level 12V	Pin Off < 3.6V	Pin ON > 8.4V

Step 3: Connecting a power supply to an analog control station and a Swift Agent A200

A control station and a Swift Agent have to share between each other a 12V source power, + (plus), - (minus), and GND (ground) PINs.

It is not recommended to use separate power supplies (due to different voltage levels) is not recommended as well as to use the control station’s power supply (for providing the analog station with power).