NEMS Linux requires just one argument for the check_tcp check command: the port number to check.
Then go generate your config and if you set your intervals correctly, all should be a-okay. If not, expand the error message to see where you went wrong.
NEMS Linux includes a dummy port listener running on port 9590. The port listener is cleverly called 9590, and does nothing other than reply that it is up. This can be used to simulate a port on another device.
Let's setup a service monitor on the NEMS host to warn us if port 9590 ever goes offline.
Once the new config is running, try failing the service by opening Monit Service Manager, click on the Process named 9590, and then click “Stop service”. You'll notice within 30 minutes the status of 9590 will show as a problem in all status views (Eg., NEMS TV Dashboard, NEMS Adagios, Nagios Core), and after 60 minutes you will receive a notification (assuming your notifications settings are configured).
Once you have received a notification, visit NEMS Adagios to Acknowledge the outage.
Then, return to Monit, open the 9590 Process, and click “Enable Monitoring”. This will re-load 9590 and you'll soon see it change to a Recovered state.
Another fun experiment is to try changing your “First Notification Delay” on the NEMS:9590 service in NEMS NConf and disable it again.