Modbus Rx/Wx probs with DL06.....

[poppabear]

I have an DL06 that port2 is connected via 232 to a SureServo Drive, I am using the modbus protocal standard RTU. On port1 I am hooked to an EZTouch Panel.

What happens is it works a little here and there, then locks up, and the coms drop out of the HMI. If controlling the SS drive through the Modbus it is a **** shoot if it works or not.

I have checked all the wires, Device numbers, protocol types for matching. The PLC just doesnt seam to be able to recieve info from the Drive. (The parameters are all mapped per the manual as well).

I had heard rumor that there is an issue between Port1 and Port2 when one of the ports is running Modbus and the other is something different. Another guy told me I should run 422 to the Drive instead of 232, (so doing that now). The 06 is device 1, and the drive is device 2.

scott

 

[bernie_carlton]

We run port 1 -> display, port 2 MODBUS very often. Though we haven't connected to the SureServo Drive we have connected to AC drives (Allen Bradley and Emerson) and servo drives (Unidrive) with very little problem. We use the DN-15TB Communication Adapter Module and run RS485. There have been very few issues.

My site http://www.theplcguy.com/Modbus/Index.htm has some info regarding the setup to a Commander SK (Emerson) drive. Maybe it will help.

 

[MASEngr]

Turn off the non-MODBUS protocols. I'm running a DL-06 with 2 DL-05 slaves (ISOCON) over RS-485. I've got a logging device on Port1 (which isn't quite working yet) but it's reading and writing via the network. I was having a lot of trouble until I turned off the other protocols (AD suggested it.)

You might also have to turn up the RTS on and off delays.

Are you using the instruction alternation bits like they suggest in the manual? Only the first MRX / RWX instruction encountered in the logic will execute, so you MUST put in code like they've got on page 4-28 of the manual. (D06uservol1.pdf)

  sp116   c0

  -|/|----|/|-----MRX

                 |

                 |-(SET)

                    c0

  sp116   c0

  -|/|----| |-----MWX

                 |

                  |-(RST)

                    c0

  

 

[poppabear]

Bernie and MASEngr,

The problem that I am having is not related to the Port Protocol. I am using striaght Modbus only nothing else turned on, on port2.

I am reading in 12 Elements and writing out 5 Elements. I have switched the system over to 422 incase it was an 232 issue. The problem is still there.

The problem occurs when BOTH the EZTouch panel and SureSurvo are plugged into Port1 and Port2 respectivly. The EZ touch works great at com'ing with the PLC, until I plug in the SS. Then the HMI "Hangs" and gives me a com time out error to port1.

Per the SureSurvo documentation, I am using MWX/MRX rungs (I was using standard RX/WX), but per ADC's suggestion I swithed to the Modbus direct com type so I didnt have to convert. I have tried settin my Baud rate speeds, down, I have tried setting various time outs all to no avail. One of the ADC techs told me that I there may be an "Undocumented" issue with Modbus element reads/writes for elements over 4. (I have cut down the elements to test this, still no luck).

I am also running serial protocol: 8-O-1 per ADC's recommendation for both the drive and SS. The data I am sending to the drive is BIN as well per thier doc.

It will not read from the drive no matter what I do, and I have gone over, and over the drive/PLC setups with ADC's Tech staff. I have even gone as high up thier food chain as you can go, and no success. We have even did the scratch pad/memory wipe, of both the PLC and SS and redid everything. And they had me check all my setting over the phone........... and all should work but it doesnt. It is a brand new PLC, SS and HMI all with latest firmware........

I guess it is possible that I got a bad PLC or SS or EZ Touch...

I am realy in a Crack here, I am suppossed to get the control for this machine to the shop so they can start construction......and I am hosed...........

If your Really, Really board or feeling generous, you can call and ask for Scott in Controls Engineering at Sawing Systems, 865-525-0600...........

Thanks in advance,

Scott

 

[jgreenewv]

Just out of curiosity, have you checked grounding? If the PLC, touchscreen, and SureServo are at different ground potentials, it could throw noise back onto your communications cabling. Also, if your system can work this way, have you tried unhooking the EZTouch and watching the port activity lights on the 06 to see if it appears it is communicating properly with the SureServo?

 

[poppabear]

yes grounding is good

 

[cjh]

So you said that the EZ Touch will comm. good to the PLC if the Sure Servo is not plugged in but will the Sure Servo comm. good if the EZ Touch is not plugged in?
If they work fine by themselves but not when they are both plugged in, I would bet huge amounts of money that it is a grounding issue.

 

[poppabear]

Well you would have lost your money......

The Problem turned out to be a BAD SureSurvo Driver... (the one I used was brand new, but after hours and hours on ADC tech support, they decided I must have a bad drive). I got the new drive this AM, plugged it up and BLAMO it is working like gang busters!!!!

The only other Glitch is their IS some kind of Com issue that is between Port 1 and Port 2 on the 06. It is a bug somewhere between the EZ touch and the 06 and the 2 com ports....

I plugged in a "Com" module same type as the port 2 and the EZ touch works great now, it no longer gives me the PLC conection time out error it was giving me earlier.

I will get intouch with EZ Automation and see if they can do some kind of firm ware update to fix the issue. I have other brand monitors like C-More panels that when I load the same kind of screens/functions on them and plug them into the port 1 where the EZ touch was, they give me NO problem.

I would like to Thank all of you who offered such great advice. Some of it I had checked already, and some I did per your suggestions......Unfortunatly, or Fortunatly depending on your point of view, it ended up being Bad (but brand new), hardware.

scott