Ser2usb stops when attached to PC

I have the Fez Panda II Ultimate Kit. I’ve hooked up the Connect Shield and the Ser2USB E-Block. I’m running off USB.

My program is a simple loop that is writing the current time out the serial port.

If I don’t have the PC attached to the USB port on the Ser2USB E-Block the Tx led blinks brightly (strangely the Rx led blinks faintly at the same time, despite there being no Rx data).

I’ve verified the signal is getting to the E-Block okay and appears to be valid serial data.

When I hook up the PC, the E-Block is recognized and a serial port is created. But simultaneously the E-Block’s LED quit blinking. The signal is still getting to it but nothing seems to happen.

Have I overlooked some hardware configuration? Does the fact the Rx light faintly blinks in unison indicate a hardware failure of some kind?

Addendum: When I pause execution via the debugger the Rx and Tx leds still blink on the Ser2USB E-Block (provided the PC is not attached). Maybe they’re signaling some state.

Put a wire from TX to RX on the eblock, open a terminal software and see if date you type get echoed back. Now remove the wire and verify that thy are not.

Is the problem with the way the led blinks or with the data not being received at the PC?

Well I fell into the classic failure of serial communication. I had the Rx/Tx wrong.

I was expecting the Rx / Tx swap to happen after the E-Block, not before. Once I swapped the connectors at the Fez Connect board the time stamps were being visible in the PC’s hyperterminal.

Thanks for your quick attention.