Direct Print Without Internet Connection

You can still use ForNAV Direct Print if you have an on-premises installation of Business Central without a connection to the Internet. This is a guide on how to set it up and optimize the performance.

No Internet

Usually, the direct print functionality will use the Internet connection to send a signal to the locally installed ForNAV Direct Print service when a print job is ready. However, this is nice but not necessarily crucial in an on-premises installation.

When monitoring the print queue on Business Central, the local service uses two channels: direct to Business Central and via the online signaling service. When running in an offline environment, you simply disable the online channel.

Configuring the Service

Since version 6.3 of the service, you can use a configuration file named config.json to set up the communication channels. Here is how:

Create a file name config.json at the following location:

C:\ProgramData\ForNAV\Direct Print\Configuration\config.json

The default content of this file can look something like this:

{
    "Version": 1,
    "Environments":
    [
        {
            "Name": "default",
            "Strategy": 
            {
                "SignalHub": {
                    "Intervals": [
                        { "Duration": 5, "LocalWait": 0 },
                        { "Duration": 60, "LocalWait": 1 },
                        { "Duration": 600, "LocalWait": 2 },
                        { "Duration": 3600, "LocalWait": 3 },
                        { "LocalWait": 10 }
                    ]
                },
                "PrintQueue": {
                    "Intervals": [
                        { "Duration": 5, "LocalWait": 0, "RemoteWait": 5 },
                        { "Duration": 120, "LocalWait": 10, "RemoteWait": 0 },
                        { "Duration": 3600, "LocalWait": 30 },
                        { "LocalWait": 60 }
                    ]
                }
            }
        }
    ]
}

This will configure the polling intervals for the online service (SignalHub) and the direct connection (PrintQueue).

Removing SignalHub intervals and changing the timing for PrintQueue can optimize it for offline use.

{
  "Version": 1,
  "Environments": [
    {
      "Name": "default",
      "Strategy": {
        "SignalHub": {
          "Intervals": [
          ]
        },
        "PrintQueue": {
          "Intervals": [
            { "Duration": 10, "LocalWait": 0, "RemoteWait": 3 },
            { "LocalWait": 2 }
          ]
        }
      }
    }
  ]
}

After saving the config.json file, restart the ForNAV Direct Print service to activate the new configuration.

Disable signaling

If you changed the configuration to not use the signaling hub, you should also disable signaling in Business Central. Go to the page ForNAV Direct Print and File Setup to disable it.