For what it is worth, the RJ connector on the Serial device has the following
pinout as referenced by the device:
Pin1 - RS232 In
Pin2 - +12V
Pin3 - RS232 Out
Pin4 - Gnd
Don't you think this might mean that pin 1 is the receiving pin? If that's true, you have to connect T1OUT to pin 1 of this connector and R1IN to pin 3 of the connector. I would try to measure the pins before connecting to avoid producing a short circuit.
It is connected correctly as I don't get the serial from the panel T1OUT to pin 1 of this connector and R1IN to pin 3 of the connector ... I tried it just to make sure.
On another note, I was successful in reading and writing to the control panel with a USB2Serial converter which I built an interface to the RJ4 connector...
Must be something in the way the serial port & USB are shared on the Arduino that keep me from reading and writing to the control panel...
thanks for your help