Oh, one other thought: On some models of the InnForm, the baud and parity for the printer could be set differently from the B/P of the SMDR. make sure that it matches both ways. It's something like, go into manager's mode, select program 14 (or something like that), select the right serial code... like maybe "93" means "1200-7S1 In and 600-8N1 out."

Remember that in serial, both ends of the cable need to be at the same speed for each set of devices. EL and Innform need to agree; Innform and printer need to agree.

There should also be a little green light on the Innform that flashes when you receive SMDR.

Remember to test from a CHECKED-IN room number.