Chained Jrks and Pololu Protocol

I have a stack of five Jrks with unique device IDs 1-5. The master has a USB cable plugged into it, and is set to USB Chained mode. Each of the slaves is set to UART mode with a fixed baud rate of 9600, and each has its RX line tied to the TX line of the master. It’s so close to working, but I must be misunderstanding some little thing. I downloaded the Pololu Serial Transmitter to do this testing. If I try to send a Set Target High Resolution command to device #4 (i.e. 0xAA 0x04 0xDD 0x64), then all five motors start spinning, which is obviously not what I want. However, if I then send a Motor Off command to device #3 (i.e. 0xAA 0x03 0x7F), then motor #3 stops spinning, and the others keep going. This makes it apparent that individual devices can respond to commands, but only the Motor Off command. What am I missing? Thank you in advance for any help you can provide.

Your Set Target High Resolution bytes (0xAA 0x04 0xDD 0x64) are wrong. When you are using the Pololu protocol, the command byte must have its most-significant bit (MSb) cleared. So try sending 0xDD minus 0x80 instead of 0xDD. --David

Gahhhh, I knew it had to be something tiny. Thank you so much… you’re a lifesaver.