[RC232] Is the RC11XXHP-RC232 series pin compatible with the low cost family RC11XX? Is there a possibility that the additional pads on the product PCB n31 to n 42, short or connect to a trace or via under the RC11XX module ?

The RC1180HP-RC323 is pin compatible with RC1180-RC232.

Note that the HP variant draw higher current and some of the do-Not-connect pins have different polarity on RC1180HP.
(e.g if you ground a pin marked not-in-use for RC1180, this pin might be used to control PA and will give problem fir RC1180HP.)

There are routing and via on the bottom side of RC11xx, with solder resist covering.
If you have routed signal under module there will only be 2 solder resist film between those line.
If you have bare pad under the module, this is even worse.

Last Update: August 8, 2017