panelview comms

ok, so I've programmed my PV550 touch screen and all seems well. I downloaded to it using the RS232 port and a 1747-PIC device driver. After some very useful information from you guys, I have (I think) sorted out how to map addresses within the PV to the logix5000 plc. I have been downloading to the PLC using DF1 direct point to point connection. Now I want to disconnect my laptop, connect the PV to the PLC and go. Thats where the problem lies, it don't go any suggestions????

Is the PLC in run mode? any errors show up?

I get error 612 'no available nodes on network' or something similar on the pv and there is no response from the RS232 LED on the controller.

I'm Really rusty on AB stuff, but it sounds like you need to reconfigure the comm port on the PV...lets see if some of the AB experts can chime in on this one.
David
beerchug

The simple answer is that you need to change the ControlLogix CPU serial port from DF1 protocol mode to DH-485 protocol mode. Go into RSLogix 5000, right-click on the Controller folder and choose Properties, then go to the System Protocol tab.

There's a more complex answer, about using DF1 versus DH-485 for this application. We can talk about that later.. I'm going to go watch the President do his Truman impression.

The problem is that if I do that, I can no longer communicate with the plc with my laptop. I only have 1 RS232 port and if I set the PLC to DH485, the only way to get it back seems to be to disconnect the battery to reset the ram. This obviously is very long winded and I can only assume that there is an easier way of setting up the laptop, plc and panelview so that they can all be interconnected. Is there any benefit in fitting a comms module on the plc to enable the panelview to be connected from this, leaving the cpu serial port free for programming???

Hi Paneltech. If you do configure the Logix port to 485 you can still communicate with it using the pic driver in linx but not using the PIC itself. Connect to the port using the same cable as for 232 (1746-cp3 or 1756-cp3. Only difference in these cables is a thinner end on the 1756 to fit behind the closed door on the cpu), fire up the pic driver and you will be straight on line.

A better way is if you have a spare enet card is to plug it into the rack and connect via it. Regards Alan Case

Thanks Alan, I'll give it a shot

John

Any problems just post back here. Alan

I can't get online with my 1756-L1 controller running V11 firmware when I use RSLinx 2.41 and the DH-485 driver. I can 'see' the processor in RSWho, and browse it's backplane, but I can't get RSLogix 5000 to go online.

I know that you can successfully go online with CompactLogix when it's in DH485 mode, and I haven't found anything that says I shouldn't be able to do the same with ControlLogix, yet the results are clear.

If you only have a controller and a PanelView in your system, and they are less than 50 feet apart, the best protocol to use is DF1 Full Duplex over RS-232. That allows the fastest communication speed between the PanelView and the controller, while permitting the use of the default DF1 driver to communicate with the controller.

DH-485 is only necessary if you have more than two networked devices or need 4000 feet of cable between them.

If you have a PanelView 550 terminal that uses DH-485 comms firmware with RS-232 ports (both printer and comms), then you may be able to load DF1 firmware into it. Give your A-B dealer a call and make sure you understand the upgrade procedure before you start (!).

I have been able to set the controller to DH485 and can communicate with it via laptop. Similarly, I can also communicate with the panelview using the same pic driver. I have the following problems.

1.When i connect the panelview to the serial port of the controller I get error 612 no nodes active on the network. I also seem to have no communication between the two (no rs232 led flicker! just slow flashing

2.I cant find a way of configuring the panelview in the control logix software ie as a module, without using an additional hardware module.
All I want to do is use the controller serial port.

3.For some reason I also have the message I/O not responding despite having configured the I/O, being able to force outputs on and off remotely and being able to execute code. Both the I/O led on the controller and the indicator in the main controllogix screen are flashing.

Surely life is simpler than this!!!???

"Surely life is simpler than this!!!???"

Welcome to the world of Allen Bradley communciations. Nothing against Ken, but A-B has more incompatible protocols, inconsistent hardware, lousy documentation, obscure configurations, hidden pin-outs, and arcane and tortuous communications blocks than any other PLC supplier I have run across. This confusion and frustration is just another hidden tax included with the use of Rockwell software, just like the annual renewal (excuse me, maintenance) fees on their software.

Bravo, Tom, on the first correct use of the word 'tortuous' in 2003 !

paneltec, you have two separate problems here.

The I/O LED on a ControlLogix CPU only indicates a failed scheduled connection, such as an I/O module being removed or mismatched. It does not indicate a failure of an unscheduled connection, like a DH-485 message or an RSLogix 5000 session. Look in the I/O configuration in the Controller Organizer and you're sure to find a yellow triangle with an exclamation point in it for one or more objects in the I/O tree. The 'connection' tab for these I/O entries generally gives you a good description of the problem.

You do not have to enter a DH-485 PanelView as an I/O device in ControlLogix. You do for I/O type network PanelView configurations like DeviceNet, RIO, and scheduled ControlNet and EtherNet/IP.

On my Logix CPU, the RS232 LED comes on solid green when I connect RSLinx via RS232 using the "1747-PIC/AIC+" driver. It goes off when I disconnect the cable. If I plug in with RSLinx set for the same node number as the ControlLogix CPU, I get a green LED that flashes off about every three seconds. This indicates a duplicate node number conflict, and is easy to remedy; just change the node number of the RSLinx station (or in your case, the node number of the PanelView terminal).

On simple DH-485 networks I generally make my programming software Node 0, my controller Node 1, and my operator interface Node 2. I then change my 'Maximum Node Number' from 31 to 2, in order to save on token-passing traffic.

Hi Paneltech. For this connection I am not sure which cable you should be using as I have always used AIC+ in the circuit. Ken might be able to help here.
And Tom, AB has so many protocols because you can do so much with them. (you just have to know how)
Regards Alan

I don't object to the number of protocols available, Alan. And while I freely admit I'm not an A-B communications guru, I'm not looking for my HNC either. I've used a lot of communications links over the years, and even written a couple of protocol drivers. Without a doubt A-B is the most difficult to design, configure, and get set up.

What I object to is the need for special adapters because DH-485 doesn't always work well with other RS-485 devices, and even including some within the A-B line. I object to needing three or four manuals for every project because no single manual covers the topic adequately. I object to A-B using null modem cables for the SLC, straight through cables for the PanelViews, that silly proprietary sort of DIN-8 pin for MicroLogix (but not all of them since there's a DB-9 on the 1500), and the mystery pinout RJ-45 on the SLC/503. I object to having to pay extra for my HMI for A-B use because of the fees. I object to A-B not allowing any kind of star topology on THEIR RS-485 systems. I object to being restricted to using THEIR AIC+ to get to RS-485 from RS-232, when other PLC comm links actually conform to the standard and allow me to use the one I like best. I object to the factory tech support guy telling my engineer in the field "I don't know which communciations block structure is right - just keep trying the different examples until you get one to work." I object to having to use one program structure and comm interlocking if I have four communcations blocks, but a totally different one if I have five.

I could go on and on. I'll post an example tomorrow, and solicit some assistance on a problem that has stumped our distributor tech support, who usually come through for me.

(Thanks for listening - that rant has been building up for a while.)