We had a client who was having difficulty getting his program backed up on his Allen Bradley Panelview 550 display (2711-B5A2). He said that he was fairly certain that he was supposed to use the 1747-PIC box (the RS485 interface used to talk to early SLC5 PLCs) to communicate with it, and it should use Rockwell's PanelBuilder32 software to transfer the files, but for some reason it would not communicate.
We had run into this before, so I had him walk me through his procedures to make sure I was correct about what he was doing wrong.
He had taken the 1747-PIC box and connected it to the RJ-45 connector on the panelview 550 (marked RS485) and then opened up RSLinx to start communications. For some reason he never sees the panel. He tried changing the baud rate and the drivers used in the RSLinx software to no avail.
I explained to him that the 1747-PIC box gets its power from the PLC connection, not the PC's serial port. The Panelviews do not put power out on those RS-485 ports, so the PIC box cannot power up. This was his problem.
The solution is a bit odd. you can either make a pigtailed cable to inject the power needed into the connector (to directly connect to the panel), or you can daisy chain it through an SLC5 PLC. This latter method is what we used.
We hooked the panel up to the PLC CPU with a 1747-C11 cable (just like the cable on the PLC side of the PIC box) and then connected the PIC box to the PLC just as we normally would to talk to the PLC. The programs on the PLC CPU or the panel are irrelevant for this purpose. They could be running, faulted, or blank. it doesn't matter.
We then fired up Rockwell's RSLinx software, loaded the PIC driver, and checked for connectivity. we saw both the PLC AND the Panelview 550 listed. RS-485 is addressed serial, with each node on the daisy chain having it's own node address. That lets you talk to multiple devices using the same connection.
Once RSLinx saw the panel, we could start up Rockwell's PanelBuilder32 software and transfer the program off the panel for backup, modification, or whatever was needed.