Can one UIRT control two identical cable set top boxes?

I have two cable TV feeds into a dual-tuner card in my PC controlled by Beyond TV .9.2. Works great.
Now Comcast will be switching to all-digital and I have two STB that I will insert into the mix. I plan to use USB-UIRT to control the STB instead of direct control of the tuners on the card. Pretty standard stuff, I think.
However, having never used a IR device in any automated way, I don't know if I need 2 USB-UIRT devices or if one will control both STBs. ANyone know?
Now Comcast will be switching to all-digital and I have two STB that I will insert into the mix. I plan to use USB-UIRT to control the STB instead of direct control of the tuners on the card. Pretty standard stuff, I think.
However, having never used a IR device in any automated way, I don't know if I need 2 USB-UIRT devices or if one will control both STBs. ANyone know?