I-tach flex serial control

The serial control from the flex unit is not able to control a sony projector. I have confirmed that the settings on the unit are correct but it is not being accepted by the projector. I have verified from a the Hercules terminal program that the command is correct to it but when it goes to the projector it fails. i am able to use the same cables and control the projector from the terminal program. Same settings that are in the flex web UI.