You should probably disable the termination character on the Serial Configure. Does the device send a response? Since you are sending binary data, it would probably respond with binary and a termination character would cause the response to end early if the it happened to be a part of the data stream.
Are you sure your checksum is correct? Are you data bits, stop bits, and parity correct?
Have you communicated with it using any software they provided to make sure the communication stream is correct?