Hi folks, I would appreciate any help on this topic. I have a AB 1500 with a flashing fault light. This fault light occured when one of packaging line mechanic tried to replace the back up battery, according to this the program is lost, I want to download the application program but everytime I try communicacion failed. I'm using a serial 9 pins to USB cable. I've tried different cables with same result. This unit has a communication push button with three position, I switched to prog mode but still the same. I do not have much experience on this type of controller. Once again folks, I would appreciate any help.

If the controller has not been damaged, then you can get communications to it by:

1. Move the PROG/RUN toggle switch to the PROG position.
2. Press the DCOMM button until the DCOMM LED illuminates solid green.
3. Connect to the Channel 0 serial port (the 8-pin round one) with a 1761-CBL-PM02 cable.
4. Use the DF1 Auto Config feature in the RSLinx Classic DF1 Full Duplex driver to configure the DF1 driver.

The principal gotcha in your situation is the USB/RS232 converter. Not all USB/RS232 converters work correctly with the Autoconfig feature, so set the DF1 driver for 19200 baud, 8 data bits, no parity, 1 stop bit, controller type SLC/Micro/PanelView and No Handshaking.

You also need to be certain about which COMx port your USB/RS232 converter has been assigned by Windows; this should show up in the Windows Control Panel under "Ports".

It is possible that your mechanic damaged something on the main board by attempting to replace the backup battery. The MicroLogix 1500 batteries are not made to be replaceable; I have some of these controllers that have spent 99% of their lives on the shelf and are still holding their programs 8 years later.

Thanks Ken, this will be very helpful