Common issues with Classic GrainGage EM Sensor upgrades

25 Feb 2010

There are three primary causes of problems after upgrading an HM-1000b Classic GrainGage with a new EM sensor.

1. The HM-401 SCCU must have a digital modification performed. If the old HM-405-4G capacitive sensor reads correctly, but the EM sensor does not, this modification may not have been performed.
2. All HM-1000b Classic GrainGages manufactured before 1998 require a special AES HM-0110 EM sensor adapter cable; the sensor will not work without this cable. (The EM sensor adapter cable should not be confused with the 11532 HM-405G moisture adapter cable.) If you are unsure of your GrainGage’s manufacturing date, check to see whether the GrainGage has a wiring harness inside or a breakout box. Pre-’98 GrainGages have gray and black cables (a wiring harness) potted into a box beneath the middle shelf of the GrainGage on the right side; these cables lead to connectors for the different components. All post-’98 GrainGages have a breakout box with discrete connectors on the box for the different sensors, limit switches, and actuator cables. Adapter cables are not required for post-’98 GrainGages.
3. The EM sensor requires the HM-401 SCCU console to have FOS version 3.4 firmware installed. If you have an earlier FOS version on the SCCU, you will experience EM sensor communications failures or other problems.

Please contact Juniper Systems Support for assistance if you have any of the problems above.