Siren for Police - Programmable - Signal change from HORN to SIREN SOUND

Job ID: 35831488

Budget: $10 – $30 USD

Siren for Police - Programmable

Hello we have here a SDF104H from Axixtech Juluen in Taiwan, the problem is this siren have a controller with RJ45 with different buttons and more.

Than we have a HRT (Horn Ring Transfer) Signal with PLUS and MINUS, when we give here a PLUS than go only on a HORN SOUND by the Loudspeaker in the Lightbar.

We need here the Sound from the Sirenen Button.

Which solutions can you offer to change Firmware that the SIGNAL is SIREN ON/OFF?
How can we read the Firmware or change this Signal ?