INVREP indicates an invalid reply from an addressable device, which typically points to a hardware or communication problem (Page 131, 136) [1].
This maintenance alert is specifically triggered when a detector reports a Low Chamber Value (Page 151) [1].
To resolve this trouble:
Clean the detector and re-check the chamber reading (Page 152) [1].
If the reading remains outside the recommended range or the hardware fault persists, replace the detector (Page 152) [1].
