@hannahlb if I understand you – you have 4 geographically distributed ISCO samplers (say more than 100m apart) and you would like to trigger them when a threshold is exceeded from a Solinst level sensor. The trigger would be communicated via messages on the telemetry NB-iot?
Probably the best way to think about it is in stages
1) figure if this can be just done from one controller – both Solinst and ISCO
2) Then when you have got it working with one controller, can you communicate that through an mqtt message over NBIot to a remote server
3) then have the three or four other remotes subscribe through mqtt NB Iot to the notification.
While this could be sketched on a whiteboard quite easily – ModularSensors only does north bound (one way into the cloud) comms through an mqtt host.
However, looking at the ISCO 6712 manual, the issue may be how to trigger the ISCO 6712 to start. If there is an external connection it could work. Or program it to run just once when powered up – and then manage the power application as the trigger. Another way might be to stimulate an SDI-12 instrument – create a dummy instrument as a trigger method. All of it is probably a lot of software work, which can take a lot of time and also trial and error having extra equipment.