RS232 problem between LPC2106 and SSC-32

Dear all,
I am using a LPC2106 chip to control the Lynx 5 arm.

What I have done are:

  1. Put the two right jumpers on, upload the code to the SSC-32.
  2. Pull off the two right jumpters, connect the PC with the LPC2106,
    monitor the output of the RS232 from the LPC2106 through
    Hyperterminal, and the result is correct.
  3. Connect the PC directly to the SSC-32, and send the command
    manually to the robotic arm through Hyperterminal, and the arm moves
    correctly.
  4. Connect the LPC2106 directly to the arm, and THE ARM FAILS MOVING.

This is the problem. Does anybody have this problem before? Can you please give me some recommendations?

Thank you very much.

Um… A code example, and hardware connections are a minimum to ask anyone for help on this processor…

The SSC32 has an LED that flashes when it receives data. Is it indicating receipt during the troubled setup?

No, it did not.

Make sure you’ve got the grounds connected, double check baud rates on the LPC2106 and that you’re driving the LPC2106 at the clock speed you think you are. Did you remember to cross RX/TX?

Yes, I did.

Is this connected to the DB9 or the TTL inputs? The TTL serial inputs require inverted serial data.

let me see your code