ADM3251E and ADM2587E GNDs

Hi there

I am using x1 ADM3251E and x1 ADM2587E devices to connect to my micro controller which proides a RS232 and RS-485/RS-422 interface to external hardware.  I am short of pins on my IO connector which carry the ADM3251E and ADM2587E signals -

ADM3251E - TX, RX, GND

ADM2587E - TX Hi, TX LO, RX Hi, RX LO, GND

Is it possible to share the same gnd between these devices? 

Regards

David