Michael Tallhamer, MSC, DABR
Varian IEC or (IEC 60601-2-1) is not the same as IEC 61217. The couch rotation is opposite in these coordinate systems. IEC 61217 has couch 270 on the left (looking at the gantry from the foot of couch) and 90 on the right. Varian IEC has couch 90 on the left (looking at the gantry from the foot of couch) and 270 on the right.
Hope that helps,