USB PC Interface and PACA

I encounted intricies using a USB PC interface and PACA unit for the first time. Previously I had always used an RS232 serial connection for the network connection.

I'd like to know exactly what's happening and what limitations there are.

I like to test my logic etc while looking at the application log. It seemed like my connection to a USB Interface was blocking the PACA from operating. Is this normal or something not configured properly?

Also, what about 2 networks, a USB interface on each and PACA on one network. Can I be connected to both networks viewing the application logs and have the PACA operate? (Reason for this I want to see the full application log for both networks which does not happen when connected to only one side of the bridge).

 

A PACA cannot function as both a USB PC Interface and a Logic Engine at the same time; it can only be one or the other. Whenever you make a connection to a USB PCI from a PC it stops the logic engine inside the unit from running and hands the C-Bus connection over to the PC. It does this because the PC can put the interface into lots of different modes whereas it needs to be in a specific mode for the logic engine.

A better tool for viewing the C-Bus messages is the C-Bus Diagnostic utility. You could certainly connect 2 instances of the Diagnostic Utility to a couple of USB PCI's, one on each network, and watch the network traffic on both networks independently. You could also simulate your logic from within PICED by connecting PICED to the 5500PACA using a 3rd USB cable.

 

Newman you are a wealth of knowledge, a real asset to this forum.

To clarify, I had two units, a PAC and a USB PC interface. I have not been able to put my finger on the issue, but things only seemed to be half working.

At one stage I could see in the application log (connected through the USB PC Interface) scene's activating but the relays not responding. After tech supports guidance (connecting to toolkit connected with the cable attached to the PAC, then closing, downloading the project again to the PAC) it seemed to work till the following day when I connected to the USB PC interface again. I tried to repeat the procedure but with no success. This procedure was suppose to fix a com port confusion. I don't know if thats simply making sure I was downloading to the PAC properly or if it was changing a setting in the xml/toolkit file.

Previously I've always used a laptop with a serial port with a serial interface... not a USB interface.

 

As far as Toolkit is concerned, the only difference between a USB PC Interface and an RS-232 PC Interface is the com port number. A decision was made fairly early on in the USB PC Interface development to expose it as a virtual COM port, rather than a native USB device, to give maximum compatibility with all the 3rd party software that talks to serial ports.

The PAC is quite a different kettle of fish. It still can behave like a USB PC Interface if you want but there's a few extra things happening in the bowels of the unit as it stops the logic engine operation and establishes the "serial" connection to the PC. I always find it easiest to use native USB PC Interfaces and just use the USB on the PAC for PICED project downloads.

The USB drivers evolve with things like new operating systems, signed drivers, 64-bit, etc and there's been a few "gotcha's" along the way with that, so I'd expect that what Tech Support were doing was just making sure that your PC is actually running the most recent drivers and ensuring the COM port numbers were unique and you had correctly identified which one related to which unit.