I know that hddtempwill provide temperature readings for the Western Digital Red Plus, because I’ve a Western Digital Red Plus in my Eon as well.
However, because it’s sat on the other side of a USB-SATA bridge you need to address it differently. If you take a shufti at my fork of the Python scripts, you’ll see you need to prefix the device with sata: first. You also need to address the drive, not the partition.
So instead of:
sudo hddtemp /dev/sdb1
you need:
sudo hddtemp sata:/dev/sdb
Which will work fine. However, you should get into the habit of using /dev/disk/by-id or /dev/disk/by-uuid instead, 'cos then they’re guaranteed to be the same drive each time you reboot.