AB 1747-DPS1 Port splitter issues... with video!

Hello Folks,

I'm trying to use an Allen Bradley 1747-DPS1 Port Splitter. The Control Logix PLC only has the RS232 port on the CPU card for communication. Typically, that port is being used by the Panelview 300, for sending commands to the PLC. I'd like to watch the ladder logic while the saw is operating to determine why the saw will not operate in "auto" mode. Buying an ethernet card seemed like a permanent solution to a temporary problem... plus it's much more expensive. This SHOULD work, but I cannot establish communications with the PV 300.

As an added treat, I have a *video* for you today! Please take a look at the 2 min. YouTube video and see if anything comes to mind. Feel free to ask additional questions.

http://www.youtube.com/watch?v=Cvi-M0uljRo&feature=youtu.be

Thanks,
Brian

Here's the manual....

http://literature.rockwellautomation.com/idc/groups/literature/documents/in/1747-in516_-en-p.pdf

The PanelView 300 requires a straight thru cable.

Note I have never used one, so not sure if that is going to cure your problem as the manual is a little unclear to me in showing what can be connected to what ports.

I'm at a loss to tell which AB cable is straight-through. If the current cable doesn't work, I have no other cables with the 8-pin mini DIN on one side, and the 9-pin D-shell on the other. Any ideas?

TL;DR add a null-modem adapter to the PanelView 300 port.

The DPS1 has three physical serial ports:

Controller Port (DIN8): Connected to ControlLogix Channel 0
Network Port (DIN8): Connected to PanelView 300
Prog/HMI Port (DB9): Connected to PC via USB and Null Modem adapters.

The intended use of the DPS1 is to have your HMI device connected to the Prog/HMI Port, but you have it connected to the Network port. In this case it doesn't really matter, because we are not sending MSG instructions out from the ControlLogix.

We know that the ControlLogix Channel 0 and your USB adapter both have "DTE" type serial ports.

And we know that the PanelView 300 with DF1 Full Duplex protocol terminal has a "DCE" type serial port.

A 2711-CBL-PM05 cable is, as I understand it, a 'null modem' type cable.

The fact that it is successfully connecting the DPS1 to a ControlLogix (which has a DTE type port) tends to confirm that.

So I think to make this work, you need a null-modem adapter on the PanelView 300's DB9 port. Or, a straight-through cable like the 2711-NC21.

AutomationTechBrian said:

I'm at a loss to tell which AB cable is straight-through. If the current cable doesn't work, I have no other cables with the 8-pin mini DIN on one side, and the 9-pin D-shell on the other. Any ideas?

Click to expand...

The Control Logix PLC only has the RS232 port on the CPU card for communication. Typically, that port is being used by the Panelview 300,

Click to expand...

Where is the cable that was being used for the above connection between the ControlLogix and the PV. That's a straight thru cable.

Alright... I have another video for all of you.

I changed the ports around and now have the laptop communicating through the network port, and the PV300 HMI hooked up to the Prog/HMI port. The laptop still communicates with the PLC, which is now hooked up to the Network port. But the HMI is still not communicating with the PLC, even though we've changed to the Prog/HMI port on the splitter.

Here's the new video: http://www.youtube.com/watch?v=5YRW592PyK8&feature=youtu.be

Okay, so the 2711-NC14 cable that connected the PanelView 300 to the ControlLogix is now connecting the PanelView 300 to the 1747-DPS1.

That ought to work, based on everything I have seen.

Can you verify that the PanelView and the ControlLogix serial ports are both configured for CRC error checking ? Are they both configured for 19200 baud ?

The ControlLogix serial port default error checking is BCC, which often makes it mismatch devices that are built for the SLC/MicroLogix world.

According to the installation instructions, the 1747-DPS1 automatically detects 19200 or 38400 baud and CRC or BCC error checking on the controller port (which is connected to the ControlLogix).

But both the Prog/HMI Port and the Network Port on the 1747-DPS1 only run at 19200 baud and CRC error checking.

A mismatch of port speed or error checking is the only thing I can think of that could be wrong in this system, based on what you've shown.

Ok... Here is the solution:

Go into the PV300 config screen and check the error checking. It was BCC, and it needed to be CRC. It went online immediately after making the change.

Thanks, Ken Roach, and Mike Jensen at Werner Electric in MN!