The Motorola ATAs accept pulse or tone dialing, but it sounds like you want an FXO port that can generate pulse dialing. You should be able to find a DTMF to pulse converter that you can put between your
SPA-3000 and the phone line in LocationB. These are even more common than pulse-to-DTMF converters because many COs were (and apparently, are) only capable of accepting pulse. I would really like to see Sipura's next-generation 3000 support pulse on both the FXS and FXO ports. (I collect vintage phones, so I really want FXS pulse support).