The 2456-LEM ambient conditions monitor can be setup in COMPASS for Pressure. An example device is included in COMPASS for Pressure and COMPASS for Flow. See the document below named "2456-LEM communication with COMPASS 20200214.docx" to add a 2456-LEM to COMPASS.
Here’s a view of the run window in COMPASS for Pressure with the Interface Spy window open that shows the commands sent to the 2456-LEM, and the replies.
For troubleshooting it's a good idea to troubleshoot a 2456-LEM with LEMcal software before troubleshooting with COMPASS for Pressure. See the Article at this link, LEMcal troubleshooting
If you need more assistance or have questions please contact Pressure Technical Support at the link below or call us at +1.877.355.3225