A new (or after factory reset) AG4000 needs to have an intial setup.
You need to send a command (click for more info) to the printer to set the printer to the correct applicator mode ^XSET,APPLICATOR,0,1 and ^XSET,REWINDER,1 (command must be sent one time). After factory default the applicator mode is reset and you will need to send it once more.
When sending the printjobs, please make sure that correct settings are set up in GoLabel/Driver:
1. Select option - “Applicator” in the LCD and lock the function by tapping the small lock on the left side (see video).
2. Make sure to choose applicator mode in the printer settings in GoLabel/Driver or any other label design SW.
3. Smartback feed/preprint must be turned off
The AG4000 has 3 triggering modes
1. Direct Mode (jumper on and DB15 shorted) After receiving the print job, printer prints the label immediately and application follows the printing. “Trigger” for whole process is the print file.
2. 1 Step trigger mode (jumper off, sensor connected to DB15) After receiving the print file, printer waits for the trigger signal on DB15, after receiving the signal, label is printed and applied directly.
3. 2 Step trigger mode (jumper on, sensor connected to DB15) After receiving the print file, the label is printed immediately, but not applied yet, label is being hold on the labeling pad by vacuum and is applied only after receiving the trigger signal on DB15.
The following fragment from UM has only 1 and 2 modes, as the 3rd Mode was implemented later.

The shorted DB15 connector is delivered together with AG4000

By plugging in the connector with pins 1 and 9 shored, you create full direct mode, because there is permanent start signal.
User manual for AG4000: LINK
Attached files: